#5377 improvisationOn doesn’t work in DrumStaff with altered drumStyleTable

[Simon Albrecht]

As reported by Robert Schmaus in this thread, after modifying drumStyleTable \improvisationOn won’t affect any pitches modified through the style table:

\version "2.19.82"

#(define mydrums '((snare default #f 1)))

\score {
  \new DrumStaff \with {
    drumStyleTable = #(alist->hash-table mydrums)
  } \new DrumVoice \drummode {
    sn4 sn4 sn4 sn4
    \improvisationOn
    sn4 sn4 sn4 sn4
  }
}

(output attached)

[Torsten Hämmerle]

IMHO, this is no bug but expected behaviour:

\improvisationOn will set NoteHead.style = #'slash.
So far, so good.

As soon the custom drumStyleTable contains an explicit NoteHead.style (such as #'default or #'cross), the #'slash preset by \improvisationOn will be overwritten again.

The standard drumStyleTable definitions don't use #'default but () so that these instruments won't override the #'slash set by \improvisationOn. #f instead of () will also work:

\version "2.19.82"

#(define mydrums '((snare () #f 1)))

\score {
  \new DrumStaff \with {
    drumStyleTable = #(alist->hash-table mydrums)
  } \new DrumVoice \drummode {
    sn4 sn4 sn4 sn4
    \improvisationOn
    sn4 sn4 sn4 sn4
  }
}

If the modified custom drumStyleTable uses () instead of default, just like in the standard defintions, even custom drumStyleTable definitions will work exactly like the standard.

All the best,
Torsten

[Torsten Hämmerle]

Hmmm,

http://lilypond.org/doc/v2.19/Documentation/notation/common-notation-for-percussion#custom-percussion-staves
always uses default instead of (), so it wasn't Robert's invention.

Perhaps we should change the NR to match the actual LilyPond standard definitions that never use default.