summaryrefslogtreecommitdiff
path: root/ly/articulate.ly
blob: 0414bd926b89418e9a5d966de31fe81e2ef24b54 (about) (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
%
% Copyright (C) 2008, 2009, 2010, 2011 NICTA
% Author: Peter Chubb <peter.chubb AT nicta.com.au>
% $Id: articulate.ly,v 1.7 2011-03-24 00:40:00 peterc Exp $
%
%
%  This program is free software; you can redistribute it and/or modify
%  it under the terms of the GNU General Public License, version 3,
%  as published by the Free Software Foundation.
%
%  WARNING: this file under GPLv3 only, not GPLv3+
%
%  This program is distributed in the hope that it will be useful,
%  but WITHOUT ANY WARRANTY; without even the implied warranty of
%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
%  See the GNU General Public License for more details.  It is
%  available in the Lilypond source tree, or at
%  http://www.gnu.org/licenses/gpl-3.0.html
%
% This script tries to make MIDI output from LilyPond a little more realistic.
% It tries to take articulations (slurs, staccato, etc) into account, by
% replacing notes  with sequential music of suitably time-scaled note plus
% skip.
%
% Trills, turns, mordents and pralls are expanded with rallentendo
% and accelerando taken into account.
%
% As my scheme knowledge is poor (I was teaching myself as I went), there
% is much scope for improvement.

% See: http://nicta.com.au/people/chubbp/articulate for additional
% information about how the articulate function works.

%%% Supported items:
% Articulations on a single note (staccato, staccatissimo, portato, tenuto).
% Slurs and phrasing slurs.
% Ornaments (i.e. mordents, trills, turns).
% Rallentando, accelerando, ritard and 'a tempo'.
%
% Please refer to 'MIDI output' (Section 3.5) in the Notation Reference
% Manual for a more detailed list of supported items.

%%% Technical Details:
% * Any note not under a slur or phrasing slur, and not marked with an
%   explicit articulation, is shortened by ac:normalFactor (default 7/8).
%   (Shortening a note means replacing the note with a note of a smaller
%   duration, and a rest to make up for the difference between the durations
%   of the original and the shortened note.)
% * Notes marked with articulations are shortened by factors specific to the
%   articulation as follows:
%     staccato       not under a slur: ac:staccatoFactor (default 1/2)
%                    under a slur: ac:portatoFactor (default 3/4)
%     staccatissimo  ac:staccatissimoFactor (default 1/4)
%     portato        ac:portatoFactor (default 3/4)
%     tenuto         ac:tenutoFactor (default 1/1 - by default, notes marked
%                                     tenuto are not shortened)
% * Appoggiaturas are made to take half the value of the note following,
%   without taking dots into account (so in \appoggiatura c8 d2. the c
%   will take the time of a crotchet).
% * Trills and turns are expanded. The algorithm tries to choose notes
%   within the time of the current tempo that lead to each twiddle being
%   around 1/8 seconds; this can be adjusted with the ac:maxTwiddleTime
%   variable.
% * Rall, poco rall and a tempo are observed. It'd be fairly trivial to
%   make accel. and stringendo and so on work too.

%
%%%USAGE
% In the \score section do:
% \articulate <<
%       all the rest of the score
% >>
% or use the lilywrap script.
%
% TO DO:
%
% * Dynamics.
%   * Fix quantisation for dynamics on single note (replace note
%     with tied 128th notes?) -- started, needs work.
%   * Make \fp do the right thing (loud start, then quiet).
%
% * Inegalite.  Notes on-beat steal time from notes off-beat.
%   Degree of stealing is a parameter: from 1.0 (straight)
%   to 1.5 (extreme swing).  Also fix tenuto to use this.
%
% * add accel (to match rall), and molto rall. I've never seen
%   molto accel but some composer somewhere has probably used it.
%
% * Fermata, and Fermata Lunga
% * Add more synonyms for accel and rall: rit ritard stringendo
%
% * Phrasing.
%   * Rall at end of piece
%   * Very slight accel into a phrase, rall out of it.
%   * Dynamics during a phrase????  unclear how these should be in
%     the general case
%
% * Trill algorithm needs work.
%
% * Cope with more ornaments/articulations.
%    inverted-turns, etc.
%   -- accent needs better control of dynamics.
%   -- Handling of generic ornaments (in lily, `\stopped'; in
%               most early music:  ornament this note (trill, turn
%               or mordent as the player wishes))

% * Automatic gruppetto at end of trill; better handling of
%      initial/final grace notes on trill

% * Automatic ornaments.
%   * Spot cadences and ornament
%   * Look for quaver-dotted note for trills, for example.
%   * Fill in steps. (Needs lookahead/lookbehind.)
% * `afterturn' -- a turn after the start of a note.
% * accidentals for trills and turns

% CHANGELOG
%  * Heikki Tauriainen: handle also the \portato articulation (both as an
%    explicit articulation, and as the articulation to use for slurred
%    notes marked \staccato).
%  * David Kastrup: remove redefinitions of \afterGrace and \appoggiatura
%    and let their actions be performed when \articulate is called by
%    recognizing and replacing LilyPond's default code for these constructs.
%    Cf issue 4517 in LilyPond's tracker.
%  * David Kastrup: basic 2.15.28 compatibility by using event-chord-wrap!
%    This should really be done by rewriting the code more thoroughly.
%  * From Iain Nicol: appoggiatura timings were out; add staccatissimo; fix
%    trillSpanner endpoints.
%  * Also handle Breathing events (by throwing them away).  This isn't ideal;
%    one should really shorten the note before a little.  But I don't know
%    how to do lookahead in scheme.
%  * Also ignore explicit line breaks.
%  * Add Mordents (reported by Patrick Karl)
%

\version "2.19.22"

#(use-modules (srfi srfi-1))
#(use-modules (srfi srfi-11))
#(use-modules (ice-9 debug))
#(use-modules (scm display-lily))

% PARAMETERS
% How much to compress notes marked Staccato.  CPE Bach says `as short as
% may conveniently be played, as if the keys were too hot to touch'.
% Most modern sources say 1/2 the notated length of a note.
#(define ac:staccatoFactor '(1 . 2))

% How much to compress notes marked staccatissimo.
#(define ac:staccatissimoFactor '(1 . 4))

% Shortening factor for notes marked portato (or slurred notes marked
% staccato).
#(define ac:portatoFactor '(3 . 4))

% And tenuto (if we ever implement time stealing, this should be >1.0)
#(define ac:tenutoFactor '(1 . 1))

% How much to articulate normal notes.  CPE Bach says 1/2 (and
% staccato should be `as short as may conveniently be played') but this
% sounds too short for modern music.  7/8 sounds about right.
#(define ac:normalFactor '(7 . 8))

% How much to slow down for a rall. or a poco rall.
% (or speed up for accel or poco accel)
#(define ac:rallFactor (ly:make-moment 60/100)) % 40% slowdown
#(define ac:pocoRallFactor (ly:make-moment 90/100)) % 10% slowdown

% The absolute time for a twiddle in a trill, in minutes.
% Start with 1/4 seconds == 1/240 minutes
#(define ac:maxTwiddleTime (ly:make-moment 1/240))

% How long ordinary grace notes should be relative to their notated
% duration.  9/40 is LilyPond's built-in behaviour for MIDI output
% (though the notation reference says 1/4).
#(define ac:defaultGraceFactor 9/40)

% What proportion of an ordinary grace note's time should be stolen
% from preceding notes (as opposed to stealing from the principal note).
% Composers' intentions for this vary.  Taking all from the preceding
% notes is LilyPond's built-in behaviour for MIDI output.
#(define ac:defaultGraceBackwardness 1)


% Internal variables, don't touch.
% (should probably be part of a context somehow)

% Whether to slur, or not
#(define ac:inSlur #f)
#(define ac:inPhrasingSlur #f)

% Whether the current noteevent is in a trill spanner
#(define ac:inTrill #f)

% assume start in C major.  Key change events override this.
% Could get from context, but don't know how.
#(define ac:current-key (make-music
          'KeyChangeEvent
          'tonic
          (ly:make-pitch -1 0 0)
          'pitch-alist
          (list (cons 0 0)
                (cons 1 0)
                (cons 2 0)
                (cons 3 0)
                (cons 4 0)
                (cons 5 0)
                (cons 6 0))))


#(define ac:currentTempo (ly:make-moment 15/1)) % 4 = 60, measured wholes per minute
#(define ac:lastTempo ac:currentTempo) % for 'a tempo' or 'tempo I'

% The duration of the current note.  Start at a crotchet
% for no good reason.
#(define ac:currentDuration (ly:make-duration 2 0 1/1))

% Amount of musical time (in whole notes) that we need to steal from the
% next events seen.
#(define ac:stealForward 0)

% List of events in the output so far, in reverse order, from which we can
% steal time.
#(define ac:eventsBackward '())

% Log events for the backward chain.
#(define (ac:logEventsBackward music)
  (music-map
   (lambda (m)
    (case (ly:music-property m 'name)
     ((EventChord)
      (set! ac:eventsBackward (cons m ac:eventsBackward))
      m)
     ((BarCheck SkipMusic)
      (let ((wm (make-sequential-music (list m))))
       (set! ac:eventsBackward (cons wm ac:eventsBackward))
       wm))
     (else
      m)))
   music))

% Steal time from the backward chain.  Adds to ac:stealForward (with a
% warning) if it couldn't backward-steal all that was desired.
#(define (ac:stealTimeBackward tosteal)
  (if (<= tosteal 0)
   #t
   (if (null? ac:eventsBackward)
    (begin
     (ly:warning (_ "articulation failed to steal ~a note backward at beginning of music; stealing forward instead") tosteal)
     (set! ac:stealForward (+ ac:stealForward tosteal)))
    (let*
     ((lastev (car ac:eventsBackward))
      (levlen (ly:moment-main (ly:music-length lastev))))
     (if (< tosteal levlen)
      (begin
       (ly:music-compress lastev (ly:make-moment (/ (- levlen tosteal) levlen)))
       #t)
      (begin
       (if (any (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
                (ly:music-property lastev 'elements))
        (ly:warning (_ "stealing the entirety of a note's time")))
       (set! (ly:music-property lastev 'elements) '())
       (set! ac:eventsBackward (cdr ac:eventsBackward))
       (ac:stealTimeBackward (- tosteal levlen))))))))

% Debugging: display a moment plus some text.
% Returns its moment argument so can be used in-line.
#(define (display-moment  text m)
  (display text)
  (display (list (ly:moment-main-numerator m) "/" (ly:moment-main-denominator m)))
  m
)

% Track tempo (and maybe later, other context properties)
% as they change.  Needs to better cope with saving only Tempo I,
% otherwise "a tempo" goes back to the tempo before the last change.
#(define (ac:adjust-props sym music)
  (case sym
   ((tempoWholesPerMinute)
    (set! ac:currentTempo (ly:music-property music 'value))
    (set! ac:lastTempo ac:currentTempo)
  )))

% Raise note one step in the current diatonic scale.
#(define (ac:up note)
  (let* ((pitch (ly:music-property note 'pitch))
         (notename (ly:pitch-notename pitch))
         (new-notename (if (eq? notename 6) 0 (+ 1 notename)))
         (alterations (ly:music-property ac:current-key 'pitch-alist))
         (new-alteration (cdr (assq new-notename alterations)))
         (new-octave (if (eq? new-notename 0) (+ 1 (ly:pitch-octave pitch))
                      (ly:pitch-octave pitch)))
       )
   (set! (ly:music-property note 'pitch)(ly:make-pitch new-octave new-notename new-alteration))))


% Lower note one step in the current diatonic scale.
#(define (ac:down note)
  (begin  (let* ((pitch (ly:music-property note 'pitch))
         (notename (ly:pitch-notename pitch))
         (new-notename (if (eq? notename 0) 6 (- notename 1)))
         (alterations (ly:music-property ac:current-key 'pitch-alist))
         (new-alteration (cdr (assq new-notename alterations)))
         (new-octave (if (eq? new-notename 6) (- (ly:pitch-octave pitch) 1)
                      (ly:pitch-octave pitch)))
       )
   (set! (ly:music-property note 'pitch)(ly:make-pitch new-octave new-notename new-alteration))))
)

% Shorten a note, and save the note's original duration in ac:currentDuration
#(define (ac:articulate-one-note m fraction)
  "Replace m with m*fraction"
  (if  (eq? 'NoteEvent (ly:music-property m 'name))
   (let*
    ((dur (ly:music-property m 'duration))
     (l (ly:duration-log dur))
     (d (ly:duration-dot-count dur))
     (factor (ly:duration-factor dur))
     (num (car fraction))
     (denom (cdr fraction)))
    (begin
     (set! ac:currentDuration dur)
     (set! (ly:music-property m 'duration)
      (ly:make-duration l d
       (* num (car factor))
       (* denom (cdr factor))))))
   m))

% helper routine to set duration.
#(define (ac:setduration music duration)
  "Set a note's duration."
  (let ((eventtype (ly:music-property music 'name)))
   (if
    (or
     (eq? eventtype 'NoteEvent)
     (eq? eventtype 'RestEvent)
     (eq? eventtype 'SkipEvent))
    (set! (ly:music-property music 'duration) duration))))

% Add an articulation event to a note.
% Used in afterGrace to mark all notes as tenuto, so they're not shortened
#(define (ac:add-articulation type music)
    (music-map (lambda (m)
                (if (eq? 'EventChord (ly:music-property m 'name))
                 (set! (ly:music-property m 'elements)
                  (append (ly:music-property m 'elements)
                   (list (make-music 'ArticulationEvent 'articulation-type type)))))
                m)
     music))

% Convert a long note to an equivalent set of short notes, tied together.
% This is needed to get smooth dynamics changes.
% Need to deal properly with stuff other than the notes (dynamics, markup etc)
% Still experimental, so disabled for now.
#(define (ac:to128 music) music)

#(define (ac:to128_disabled music)
  (if (or (eq? 'SkipEvent (ly:music-property music 'name))
        (eq? 'NoteEvent (ly:music-property music 'name)))
   (let* ((dur (ly:music-property music 'duration))
          (log2 (ly:duration-log dur))
         (shiftcount (- 6 log2))
         (lastm (ly:music-deep-copy (shift-duration-log music shiftcount 0))))
   (set! (ly:music-property music 'elements)
    (cons (make-music 'TieEvent) (ly:music-property music 'elements)))
   (make-sequential-music (list
                           (make-repeat "unfold" (1- (expt 2 shiftcount))
                            (make-sequential-music (list music)) '())
                           lastm)))
 music))


% absolute time in minutes of a length of music, as a rational number (moment)
#(define (ac:abstime music)
  (ly:moment-div (ly:music-length music) ac:currentTempo))

% convert absolute time (in minutes) to a moment in the current tempo
#(define (ac:abs->mom m)
  (ly:moment-mul m ac:currentTempo))


% a moment that is ac:maxTwiddletime seconds at the current tempo.
#(define (ac:targetTwiddleTime)
  (ac:abs->mom ac:maxTwiddleTime))


% Nearest twiddletime (in minutes) achievable with power-of-2 divisions of
% the original music.  (twiddletime is the time for one pair of notes
% in a trill)
% If the music has a precomputed twiddletime (e.g., from \afterGrace) use that.
#(define (ac:twiddletime music)
  (let* ((tr (filter (lambda (x)
                     (and (eq? 'ArticulationEvent (ly:music-property x 'name))
                      (string= "trill" (ly:music-property x 'articulation-type))))
              (ly:music-property music 'elements)))
         (pre-t (if (pair? tr) (ly:music-property (car tr) 'twiddle)
                 '()))
         (hemisemimom (ly:make-moment 1/64))
         (t (ac:targetTwiddleTime)))
   (if (ly:moment? pre-t)
    pre-t
    hemisemimom)))



% Note: I'm assuming early music practice of starting on the auxiliary note.
% Needs to add gruppetto if it's a long trill (TODO)
#(define (ac:trill music)
  " Replace music with time-compressed repeats of the music,
    maybe accelerating if the length is longer than a crotchet "
  (let* ((hemisemidur (ly:make-duration 5 0 1/1))
         (orig-len  (ly:music-length music))
         (t (ac:twiddletime music))
         (uppernote '())
         (note_moment (ly:moment-mul t (ly:make-moment 1/2)))
         (c1 (ly:moment-div orig-len t))
         (c2 (inexact->exact
              (round (/ (ly:moment-main-numerator c1)
                      (* 2 (ly:moment-main-denominator c1))))))
         (count (if (< c2 2) 2 c2)))

   (set! (ly:music-property music 'elements)
    (filter (lambda (y) (eq? 'NoteEvent (ly:music-property y 'name)))
     (ly:music-property music 'elements)))
   (map (lambda (y) (ac:setduration y hemisemidur))
    (ly:music-property music 'elements))
   (set! uppernote (ly:music-deep-copy music))
   (map (lambda (y) (ac:up y))
    (filter
     (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
     (ly:music-property uppernote 'elements)))

   (let* ((trillMusicElements
          (let loop ((so_far (list uppernote music))
                     (c count))
           (if (> c 1)
            (loop (append (list (ly:music-deep-copy uppernote) (ly:music-deep-copy music)) so_far) (1- c))
            so_far)))
          (trillMusic (make-sequential-music trillMusicElements))
          (newlen (ly:music-length trillMusic))
          (factor (ly:moment-div  orig-len newlen)))
    (ly:music-compress trillMusic factor)
; accelerating the music seems to put lily into an infinite loop in
; its layout and midi engines.
;    (let* ((realfactor (exp (* (/ 1.0 count) (log 0.75))))
;          (factor (ly:make-moment (inexact->exact (round (* 1024 realfactor)))
;                   1024)))
;     (ac:accel trillMusic factor))
 )))


% Copy music and strip articulations, ties, etc., for generating
% mordents etc.
#(define (ac:note-copy music)
  "return a copy of music that is only notes, no articulations, ties, slurs etc"
  (let ((new-music (ly:music-deep-copy music)))
   (set! (ly:music-property new-music 'articulations) '())
   (set! (ly:music-property new-music 'elements)
    (filter (lambda (y) (eq? 'NoteEvent (ly:music-property y 'name)))
     (ly:music-property new-music 'elements)))
   new-music))

%
% Generate a tempoChangeEvent and its associated property setting.
%
#(define (ac:tempoChange tempo)
  (make-sequential-music
   (list (make-music 'TempoChangeEvent
          'metronome-count
          tempo
          'tempo-unit
          (ly:make-duration 0 0 1/1))
    (context-spec-music
    (make-property-set 'tempoWholesPerMinute  tempo) 'Score))))

%
% Totally unfold repeats, so that the non-obvious sequencing doesn't
% confuse us.  This is necessary for time stealing to work, because
% that relies on the sequence in which we see events matching their
% audible sequence.  Also unfold multi-measure rests to equivalent
% skips, with preceding and following bar checks, so that time stealing
% can change the length of the pause without falling foul of the
% implicit bar checks.
%
#(define (ac:unfoldMusic music)
  (music-map
   (lambda (m)
    (case (ly:music-property m 'name)
     ((UnfoldedRepeatedMusic)
      (let
       ((body (ly:music-property m 'element))
        (altl (ly:music-property m 'elements))
        (rc (ly:music-property m 'repeat-count)))
       (if (null? altl)
        (make-sequential-music
         (list-tabulate rc (lambda (i) (ly:music-deep-copy body))))
        (let ((ealtl (if (> (length altl) rc) (take altl rc) altl)))
         (make-sequential-music
          (apply append!
           (append!
            (list-tabulate
             (- rc (length ealtl))
             (lambda (i) (list (ly:music-deep-copy body) (ly:music-deep-copy (car ealtl)))))
            (map (lambda (alt) (list (ly:music-deep-copy body) alt)) ealtl))))))))
     ((EventChord)
      (let-values
       (((trem evl)
         (partition (lambda (v) (eq? (ly:music-property v 'name) 'TremoloEvent))
          (ly:music-property m 'elements))))
       (if (null? trem)
        m
        (let*
         ((tremtype (ly:music-property (car trem) 'tremolo-type))
          (tremtype-log (1- (integer-length tremtype)))
          (durev (find (lambda (v) (not (null? (ly:music-property v 'duration)))) evl))
          (totaldur (if durev (ly:music-property durev 'duration) (ly:make-duration tremtype-log 0 1)))
          (tgt-nrep (/ (duration-visual-length totaldur) (duration-log-factor tremtype-log)))
          (eff-nrep (max (truncate tgt-nrep) 1))
          (tremdur (ly:make-duration tremtype-log 0
                    (* (/ tgt-nrep eff-nrep) (ly:duration-scale totaldur)))))
         (or (and (= eff-nrep tgt-nrep) (= (ash 1 tremtype-log) tremtype))
          (ly:warning (_ "non-integer tremolo ~a:~a")
           (duration->lily-string (duration-visual totaldur) #:force-duration #t #:time-scale 1)
           tremtype))
         (for-each
          (lambda (v)
           (or (null? (ly:music-property v 'duration))
            (set! (ly:music-property v 'duration) tremdur)))
          evl)
         (set! (ly:music-property m 'elements) evl)
         (make-sequential-music
          (list-tabulate eff-nrep (lambda (i) (ly:music-deep-copy m))))))))
     ((MultiMeasureRestMusic)
      (make-sequential-music
       (list
        (make-music 'BarCheck)
        (make-music 'SkipMusic 'duration (ly:music-property m 'duration))
        (make-music 'BarCheck))))
     (else
      m)))
   (unfold-repeats music)))

% If there's an articulation, use it.
% If in a slur, use (1 . 1) instead (unless the note is marked staccato,
% in which case use ac:portatoFactor).
% Treat phrasing slurs as slurs, but allow explicit articulation.
%
% Expect an EventChord.
%
% trills, turns, ornaments etc.  are also treated as Articulations.
% Split into two functions:
%  ac:getactions traverses the elements in the EventChord
%               and calculates the parameters.
%  ac:articulate-chord applies the actions to each NoteEvent in
%               the EventChord.
#(define (ac:getactions music)
  (let ((at-end-of-slur #f))
   (let  loop ((factor ac:normalFactor)
               (newelements '())
               (es (ly:music-property music 'elements))
               (actions '()))
    (if (null? es)
     (begin
      (set! (ly:music-property music 'elements) (reverse newelements))
      (if
       (not (any (lambda (m) (music-is-of-type? m 'rhythmic-event))
                 newelements))
       actions
       (append
        (let ((st ac:stealForward))
         (if (= st 0)
          '()
          (begin
           (set! ac:stealForward 0)
           (list 'steal st))))
        actions
        (cond
         (ac:inTrill '(trill))
         ((and (eq? factor ac:normalFactor) (or ac:inSlur ac:inPhrasingSlur))
          (list 'articulation  '(1 . 1)))
         ((and (eq? factor ac:staccatoFactor) (or ac:inSlur at-end-of-slur))
          (list 'articulation ac:portatoFactor))
         (else (list 'articulation  factor))))))
     ; else part
     (let ((e (car es))
           (tail (cdr es)))
      (case (ly:music-property e 'name)

       ((BeamEvent) ; throw away beam events, or they'll be duplicated by turn or trill
        (loop factor newelements tail actions))

       ((LineBreakEvent FingeringEvent MarkEvent BreathingEvent TieEvent SkipEvent RestEvent) ; pass through some events.
        (loop (cons 1 1) (cons e newelements) tail actions))

       ((ArticulationEvent)
        (let ((articname (ly:music-property e 'articulation-type)))
         ; TODO: add more here
         (cond
          ((string= articname "staccato")
           (loop ac:staccatoFactor newelements tail actions))
          ((string= articname "staccatissimo")
           (loop ac:staccatissimoFactor newelements tail actions))
          ((string= articname "portato")
           (loop ac:portatoFactor newelements tail actions))
          ((string= articname "tenuto")
           (loop ac:tenutoFactor newelements tail actions))
          ((string= articname "mordent")
           (loop (cons 1 1) newelements tail (cons 'mordent actions)))
          ((string= articname "prall")
           (loop (cons 1 1) newelements tail (cons 'prall actions)))
          ((string= articname "trill")
           (loop (cons 1 1) newelements tail (cons 'trill actions)))
          ((string= articname "turn")
           (loop (cons 1 1) newelements tail (cons 'turn actions)))
          (else (loop factor (cons e newelements) tail actions)))))

       ((TextScriptEvent)
        (let ((t (ly:music-property e 'text)))
         (if (not (string? t))
          (loop factor (cons e newelements) tail actions)
          (begin
           (cond
            ((or
              (string= t "rall")
              (string= t "Rall")
              (string= t "rit.")
              (string= t "rall."))
             (loop factor (cons e newelements) tail (cons 'rall actions)))
            ((or
              (string= t "accelerando")
              (string= t "accel")
              (string= t "accel."))
             (loop factor (cons e newelements) tail (cons 'accel actions)))
            ((or
              (string= t "poco accel."))
             (loop factor (cons e newelements) tail (cons 'pocoAccel actions)))
            ((or
              (string= t "poco rall.")
              (string= t "poco rit."))
             (loop factor (cons e newelements) tail (cons 'pocoRall actions)))
            ((or (string= t "a tempo")
              (string= t "tempo I"))
           (loop factor (cons e newelements) tail (cons 'aTempo actions)))
            (else (loop factor (cons e newelements) tail actions)))))))

       ((SlurEvent)
        (let ((direction (ly:music-property e 'span-direction)))
         (set! ac:inSlur (eq? direction -1))
         (set! at-end-of-slur (eq? direction 1))
         (loop factor newelements tail actions)))

       ((TrillSpanEvent)
        (let ((direction (ly:music-property e 'span-direction)))
         (set! ac:inTrill (eq? direction -1))
         (if ac:inTrill
          (loop factor newelements tail (cons 'trill actions))
          (loop factor (cons e newelements) tail actions))))

       ((PhrasingSlurEvent)
        (let ((direction (ly:music-property e 'span-direction)))
         (set! ac:inPhrasingSlur (eq? direction -1))
         (loop factor newelements tail actions)))

       (else (loop factor (cons e newelements) tail actions))))))))



#(define (ac:articulate-chord music)
  (cond
   ((eq? 'EventChord (ly:music-property music 'name))
    (ac:logEventsBackward
     (let loop ((actions (ac:getactions music)))
      (if (null? actions)
        (if (ly:moment<? (ly:make-moment 1/4) (ly:music-length music))
         (ac:to128  music)
         music)

      (case (car actions)

       ((articulation)
        (map
         (lambda (x) (ac:articulate-one-note x (cadr actions)))
         (ly:music-property music 'elements))
        (let*
         ((num (caadr actions))
          (denom (cdadr actions))
          (mult (ly:duration-factor ac:currentDuration))
          (newnum (* (- denom num) (car mult)))
          (newdenom (* (cdr mult) denom))
          (len (ly:duration-log ac:currentDuration))
          (dots (ly:duration-dot-count ac:currentDuration)))

         (if (not (eq? num denom))
          (make-sequential-music
           (list (ac:to128 music)
           (make-music 'EventChord 'elements
            (list
             (make-music 'RestEvent 'duration (ly:make-duration len dots newnum newdenom))))))
          music)))

       ((accel)
        (set! ac:lastTempo ac:currentTempo)
        (set! ac:currentTempo (ly:moment-div ac:currentTempo ac:rallFactor))
        (let ((pset (ac:tempoChange ac:currentTempo)))
         (if (null? (cdr actions))
          (make-sequential-music (list pset music))
          (make-sequential-music
           (list pset (loop (cdr actions)))))))

       ((pocoAccel)
        (set! ac:lastTempo ac:currentTempo)
        (set! ac:currentTempo (ly:moment-div ac:currentTempo ac:pocoRallFactor))
        (let ((pset (ac:tempoChange ac:currentTempo)))
         (if (null? (cdr actions))
          (make-sequential-music (list pset music))
          (make-sequential-music
           (list pset (loop (cdr actions)))))))

       ((rall)
        (set! ac:lastTempo ac:currentTempo)
        (set! ac:currentTempo (ly:moment-mul ac:currentTempo ac:rallFactor))
        (let ((pset (ac:tempoChange ac:currentTempo)))
         (if (null? (cdr actions))
          (make-sequential-music (list pset music))
          (make-sequential-music
           (list pset (loop (cdr actions)))))))

       ((pocoRall)
        (set! ac:lastTempo ac:currentTempo)
        (set! ac:currentTempo (ly:moment-mul ac:currentTempo ac:pocoRallFactor))
        (let ((pset (ac:tempoChange ac:currentTempo)))
         (if (null? (cdr actions))
          (make-sequential-music (list pset music))
          (make-sequential-music
           (list pset (loop (cdr actions)))))))

       ((aTempo)
        (set! ac:currentTempo ac:lastTempo)

        (let ((pset (ac:tempoChange ac:currentTempo)))
         (if (null? (cdr actions))
          (make-sequential-music (list pset music))
          (make-sequential-music
           (list pset (loop (cdr actions)))))))

       ((trill)
         (ac:trill music))

       ((prall)
        ; A pralltriller symbol can either mean an inverted mordent
        ; or a half-shake -- a short, two twiddle trill.
        ; We implement as a half-shake.
        (let*
         ((origlength (ly:music-length music))
          (gracedur (ly:make-duration 5 0 1/1))
          (gracenote (ac:note-copy music))
          (abovenote (ac:note-copy music))
          (abovenoteTwo (ac:note-copy music))
          (mainnote (ly:music-deep-copy music)))

         (map (lambda (y) (ac:setduration y gracedur))
          (ly:music-property gracenote 'elements))
         (map (lambda (y) (ac:setduration y gracedur))
          (ly:music-property abovenote 'elements))
         (map (lambda (y) (ac:setduration y gracedur))
          (ly:music-property abovenoteTwo 'elements))
         (map (lambda (y) (ac:up y))
          (filter
           (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
           (ly:music-property abovenote 'elements)))
         (map (lambda (y) (ac:up y))
          (filter
           (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
           (ly:music-property abovenoteTwo 'elements)))
         (let* ((prallMusic (make-sequential-music
                              (list abovenote gracenote abovenoteTwo mainnote)))
                 (newlen (ly:music-length prallMusic))
                 (factor (ly:moment-div origlength newlen)))
           (ly:music-compress prallMusic factor))))

       ((mordent)
        (let*
         ((origlength (ly:music-length music))
          (gracedur (ly:make-duration 5 0 1/1))
          (gracenote (ac:note-copy music))
          (belownote (ac:note-copy music)))
         (map (lambda (y) (ac:setduration y gracedur))
          (ly:music-property gracenote 'elements))
         (map (lambda (y) (ac:setduration y gracedur))
               (ly:music-property belownote 'elements))
         (map (lambda (y) (ac:down y))
          (filter
           (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
           (ly:music-property belownote 'elements)))

         (let* ((mordentMusic (make-sequential-music (list gracenote belownote music)))
                (newlen (ly:music-length mordentMusic))
                (factor (ly:moment-div origlength newlen)))
          (ly:music-compress mordentMusic factor))))

       ((turn)
        (let*
         ((dur (ly:music-property
                (car (ly:music-property music 'elements)) 'duration))
          (factor (ly:duration-factor dur))
          (newdur (ly:make-duration (+ (ly:duration-log dur) 2)
                   (ly:duration-dot-count dur) (car factor)(cdr factor))))
         (begin
          (map (lambda (y) (ac:setduration y newdur))
           (ly:music-property music 'elements))
          (let* ((above (ly:music-deep-copy music))
                 (below (ly:music-deep-copy music))
                 (newmusic (make-sequential-music (list above music below music))))
           (begin
            (map (lambda (y) (ac:down y))
             (filter
              (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
              (ly:music-property below 'elements)))
            (map (lambda (y) (ac:up y))
             (filter
              (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
              (ly:music-property above 'elements)))
            newmusic)))))
       ((steal)
        (let
         ((totallen (ly:moment-main (ly:music-length music)))
          (steallen (cadr actions)))
         (if (>= steallen totallen)
          (begin
           (if (any (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
                    (ly:music-property music 'elements))
            (ly:warning (_ "stealing the entirety of a note's time")))
           (set! ac:stealForward (- steallen totallen))
           (make-sequential-music '()))
          (begin
           (ly:music-compress music (ly:make-moment (/ (- totallen steallen) totallen)))
           (loop (cddr actions))))))
     )))))

   ((eq? 'GraceMusic (ly:music-property music 'name))
    (let
     ((first-ev
       (call-with-current-continuation
        (lambda (yield-fev)
         (music-map
          (lambda (m)
           (if (eq? 'EventChord (ly:music-property m 'name))
            (yield-fev m)
            m))
          music)
         #f))))
     (if first-ev
      (let ((fev-pos (find-tail (lambda (m) (eq? m first-ev)) ac:eventsBackward)))
       (if fev-pos
        (set! ac:eventsBackward (cdr fev-pos))
        (ly:warning (_ "articulation of grace notes has gone awry"))))))
    (let*
     ((gmus (ly:music-compress (ly:music-property music 'element)
                               (ly:make-moment ac:defaultGraceFactor)))
      (glen (ly:moment-main (ly:music-length gmus))))
     (ac:stealTimeBackward (* glen ac:defaultGraceBackwardness))
     (set! ac:stealForward (+ ac:stealForward (* glen (- 1 ac:defaultGraceBackwardness))))
     gmus))

   ((memq (ly:music-property music 'name) '(BarCheck SkipMusic))
    (let ((totallen (ly:moment-main (ly:music-length music)))
          (steallen ac:stealForward))
     (cond
      ((= steallen 0)
       (ac:logEventsBackward music))
      ((< steallen totallen)
       (set! ac:stealForward 0)
       (ac:logEventsBackward
        (ly:music-compress music (ly:make-moment (/ (- totallen steallen) totallen)))))
      (else
       (set! ac:stealForward (- steallen totallen))
       (make-sequential-music '())))))

   ((eq? 'KeyChangeEvent (ly:music-property music 'name))
    (set! ac:current-key music)
    music)

   ((eq? 'PropertySet (ly:music-property music 'name))
    (ac:adjust-props (ly:music-property music 'symbol) music)
    music)

   (else music)))



% At last ... here's the music function that applies all the above to a
% score.
articulate = #(define-music-function (music)
               (ly:music?)
               "Adjust times of note to add tenuto, staccato and
                normal articulations.
                "
               (dynamic-wind
                (lambda ()
                 (set! ac:stealForward 0)
                 (set! ac:eventsBackward '()))
                (lambda ()
                 (music-map
                  ac:articulate-chord
                  (ac:startup-replacements music)))
                (lambda ()
                 (or (= ac:stealForward 0)
                  (begin
                   (ly:warning (_ "articulation failed to steal ~a note at end of music") ac:stealForward)
                   (set! ac:stealForward 0)))
                 (set! ac:eventsBackward '()))))

#(define (ac:startup-replacements music)
   (fold (lambda (f m) (f m))
	 music
	 (list
	  event-chord-wrap!
	  ac:replace-aftergrace
	  ac:replace-appoggiatura
	  ac:unfoldMusic)))

#(define (ac:replace-aftergrace music)
   (map-some-music
    (lambda (expr)
      (with-music-match
       (expr (music 'SimultaneousMusic
		    elements (?before-grace
			      (music 'SequentialMusic
				     elements ((music 'SkipMusic)
					       (music 'GraceMusic
						      element ?grace))))))
       (ac:aftergrace ?before-grace ?grace)))
    music))

#(define (ac:replace-appoggiatura music)
   ;; appoggiature are ugly to deal with since they require a main
   ;; note following them.  We only try dealing with this followership
   ;; in sequential music
   (map-some-music
    (lambda (m)
      (if (eq? 'SequentialMusic (ly:music-property m 'name))
	  (pair-for-each
	   (lambda (elts)
	     (let ((expr (car elts))
		   (main (and (pair? (cdr elts)) (cadr elts))))
	       (and main
		    ;;stolen from define-music-display-methods
		    (with-music-match
		     (expr (music
			    'GraceMusic
			    element (music
				     'SequentialMusic
				     elements (?start
					       ?music
					       ?stop))))
		     ;; we check whether ?start and ?stop look like
		     ;; startAppoggiaturaMusic stopAppoggiaturaMusic
		     (and (with-music-match (?start (music
						     'SequentialMusic
						     elements ((music
								'EventChord
								elements
								((music
								  'SlurEvent
								  span-direction START))))))
					    #t)
			  (with-music-match (?stop (music
						    'SequentialMusic
						    elements ((music
							       'EventChord
							       elements
							       ((music
								 'SlurEvent
								 span-direction STOP))))))
					    #t)
			  (let* ((app (ac:appoggiatura ?music main))
				 (apps (ly:music-property app 'elements)))
			    (set-car! elts (car apps))
			    (set-car! (cdr elts) (cadr apps))
			    #f))))))
	   (ly:music-property m 'elements)))
      #f)
    music))

% Override \afterGrace to be in terms of audio, not spacing.
% Special handling for a gruppetto after a trill.
#(define (ac:aftergrace main grace)
  (let*
   ((main-length (ly:music-length main))
    (grace-orig-length (ly:music-length grace))
    (gracelen (ac:twiddletime main))
    (grace-factor (ly:moment-div gracelen grace-orig-length))
    (new-main-length (ly:moment-sub main-length gracelen))
    (factor (ly:moment-div new-main-length main-length))
  )
   (map (lambda (y) (set! (ly:music-property y 'twiddle) gracelen))
         (filter (lambda (z)
                  (and
                   (eq? 'ArticulationEvent (ly:music-property z 'name))
                   (string= "trill" (ly:music-property z 'articulation-type))))
          (ly:music-property main 'elements)))
   (ac:add-articulation "tenuto" grace)
   (make-sequential-music  (list (ly:music-compress main factor) (ly:music-compress grace grace-factor)))))

% An appoggiatura takes half the duration of the main note,
% or 1/3 if the note is dotted (i.e., half the undotted equivalent time)
% Somewhere around the end of the 19th, start of 20th century the rules
% changed, but my main interest is early music.
#(define (ac:appoggiatura grace main)
  (let* ((maindur (ly:music-length main))
         (grace-orig-len (ly:music-length grace))
         (main-orig-len (ly:music-length main))
         (numerator (ly:moment-main-numerator maindur))
         (factor (if (eq? (remainder numerator 3) 0)
                  (ly:make-moment 1/3) (ly:make-moment 1/2))))
   (ly:music-compress grace
    (ly:moment-mul factor (ly:moment-div main-orig-len grace-orig-len)))
   (ly:music-compress main (ly:moment-sub (ly:make-moment 1/1) factor))

    (set! (ly:music-property grace 'elements)
     (append (ly:music-property grace 'elements)
      (list (make-music 'SlurEvent 'span-direction -1))))
    (set! (ly:music-property main 'elements)
     (append (ly:music-property main 'elements)
      (list (make-music 'SlurEvent 'span-direction 1))))
     (make-sequential-music (list grace main))))