keysIntro = {
  \repeat unfold 8 R1 |
}

keysA = {
  \time 2/4
  r2 | r2 | r2 |
  r2 | r2 |
  \time 6/8
  r4. r4. |

  \time 2/4
  r2 | r2 | r2 |
  \time 4/4
  R1 | R1 |
}

keysAExtended = {
  \time 4/4
  R1 | R1 |
  %% more intense!
  \repeat unfold 4 {
    R1 | R1 |
  }
}

keysATransition = {
  \time 4/4 R1 | R1 |
}

keysVerse = \relative c {
  \time 4/4
  \key cis \minor
  cis4\sustainOn gis' cis dis8 e ~ e2.. r8\sustainOff |
  <e, b' e fis gis>2.\arpeggio <dis b' cis dis>4\arpeggio ~ <dis b' cis dis>1 |
  cis4\sustainOn gis' cis dis8 e ~ e2.. r8\sustainOff |
  <e, b' e fis gis>2.\arpeggio <dis b' cis dis>4\arpeggio ~ <dis b' cis dis>1 |
  a,2 ~ a4. <a' e' b'>8 ~ <a e' b'>1 |
  a,2 <a' e' b'>4 b,4 ~ b1 |
}

keysVerseVariant = {
  \time 4/4
  \key bes \minor
  bes4\sustainOn f' des' bes, ~ bes f' des' r\sustainOff |
  des,\sustainOn as' f' c,\sustainOff ~ c\sustainOn as' es' c,\sustainOff |

  bes4\sustainOn f' des' bes, ~ bes f' des' r\sustainOff |
  des,\sustainOn as' f' c,\sustainOff ~ c\sustainOn as' es' c,\sustainOff |

  ges8 r ges r ges r <des' f'>4 ~| <des f'>1 |
  ges,2 <ges' des' as'>4 as,4 ~ | as1 |
}

%% TODO
keysVerseHarder = \keysVerse

keysNasty = \relative c' {
  \time 6/8
  \key cis \minor
  \repeat unfold 2 \repeat volta 2 {
    <gis cis e>2. ~ | <gis cis e>2.   |
    <a bis dis>2.   | <a bis dis fis> |
    <gis cis e>   ~ | <gis cis e> ~   |
    <gis cis e>   ~ | <gis cis e>     |

    <gis cis e>2. ~ | <gis cis e>2.   |
    <a bis dis>2.   | <fis a bis dis> |
    <e gis cis>   ~ | <e gis cis> ~   |
    <e gis cis>   ~ | <e gis cis>     |
  }

  <gis cis e>2. ~ | <gis cis e>     |
  <a bis dis>     | <a bis dis fis> |
  <gis cis e> ~   | <gis cis e>     |

  <g ais cis e> | <fis gis bis dis> |

  \key e \minor
  <fis g b e> ~ | <fis g b e> |
  <fis a c dis> |  <dis fis a c> |
  <e g b> ~ | <e g b> |
  <c dis fis a> |  <dis fis a c> |

  <e g b> ~ | <e g b> |
  <e g ais cis> | <a b dis> |

  <b e g> ~ | <b e g> |
  <c dis fis a> | <a c dis fis> |
  <b e g> ~ | <b e g> |
  <c dis fis a>2 r4 | <b dis fis a>2. ~ | <b dis fis a>2. |
}

keysWaltz = \relative c'' {
  \time 3/4
  r4 <g b> <e g> | r <g b> <es g> |
  r4 <g b> <d g> | r <g b> <cis, e g> |
  <c e g b>2.\arpeggio | <c e a> | <c e>2 <c e>4 |
  <c e g b>4. <c e a>4. | <c e>2. ~ | <c e>2. |
  <d fis b>2.\arpeggio | <d fis a> | <d e>2 <d fis>4 |
  %% TODO
  <d fis b>4. <d fis a>4. | <cis e>4 <c fis> <b g'> |
  \key fis \minor
  <bes e gis>2. | <bes cis fis>2. | <bes cis>2 bes4 |
  <a e' gis>4. <a cis fis> |
}

keyboard = \new PianoStaff <<
  \new Staff \relative c' {
    \clef "treble_8"
    %% Intro
    \time 4/4
    \set PianoStaff.midiInstrument = #"electric piano 2"
    \repeat volta 2 \keysIntro
    \repeat volta 2 \keysA
    \keysAExtended
    \keysATransition
    \repeat volta 2 \keysVerse
    \keysVerseVariant
    \keysVerseHarder

    \repeat volta 2 \keysA
    \keysAExtended
    \keysATransition

    \keysNasty
    \keysWaltz
  }
>>