Re: RemoveEmptyStaffContext

[Nicolas Sceaux]

Le 10 févr. 09 à 10:40, Johan Vromans a écrit :

> Hi,
>
> I have a score with 3 voices, A, B, and C.
> Voices B and C have a lot in common. For about half of the score the B
> parts is identical to the C part.
>
> By specifying rests in voice B where it is identical to voice C, and
> using \RemoveEmptyStaffContext, LilyPond can eliminate printing of
> voice B. That's good. And a space saver.
>
> But, not surprisingly, this makes the generated MIDI less useful. I
> split the MIDI into separate parts for the individual voices, and now
> voice B will have large gaps where it should sound the same as voice
> C. I hope it is clear what I mean.


You can make the second staff removable where the two voices are the  
same.
For instance:

\version "2.12.2"

startHaraKiri = \set Staff.keepAliveInterfaces = #'()
stopHaraKiri = \unset Staff.keepAliveInterfaces

voiceA = { c'1 d' e' f' g' }
voiceB = { e'1 d' e' f' e' }
%% voice A and voiceB are the same on bar 2, 3 and 4:
haraKiriVoiceB = { s1 \startHaraKiri s1*3 \stopHaraKiri s1 }

\score {
  <<
    \new Staff << \voiceA \repeat unfold 4 { s1 \break } >>
    %% make the second staff removable:
    \new Staff \with { \override VerticalAxisGroup #'remove-empty = ##t
                       \override Beam #'auto-knee-gap = #'()
                       \consists "Hara_kiri_engraver"
                       \remove "Axis_group_engraver" }
    << \voiceB \haraKiriVoiceB >>
  >>
}

nicolas