\version "2.19.43"

\header {

  texidoc = "The halfopenvertical articulation is available."

}
#(define mydrums '(
         (hihat         cross #f                 5)
         (openhihat     cross "open"             5)
         (closedhihat   cross "stopped"          5)
         (halfopenhihat cross "halfopenvertical" 5)))

\new DrumStaff <<
  \set DrumStaff.drumStyleTable = #(alist->hash-table mydrums)

  \drummode { hh4 hhc hho hhho }
>>