Re: AccidentalCautionary in NullVoice

[Keith OHara]

On Sat, 16 Aug 2014 11:29:29 -0700, Dan Eble <address@hidden> wrote:

> On Aug 11, 2014, at 02:43 , Keith OHara <address@hidden> wrote:
>
> > I'll still put NullVoice in \score by default, so it doesn't interact with the 
> > accidental engraver, or anything else that we haven't noticed yet, and let you  
> > \new Staff \with { \accepts NullVoice } when you really want NullVoice included 
> > in the Staff.
>
> Isn’t this backwards?

Not if there are uses of NullVoice as a completely invisible voice.  If 
NullVoice does not show its own accidentals, alterations on NullVoice notes 
should not count for figuring which further notes need visible accidentals.

> The bugs with part-combined accidentals seem to arise from the part combiner’s 
> destroying information (and creating misleading information) by reassigning 
> notes to other voices.  Instead of removing the NullVoice which has the 
> valuable original information useful to the Accidental engraver, shouldn’t 
> there be a way to make the Accidental_engraver ignore the voices created by the 
> part combiner?  Here is an example that shows combined issues with accidentals, 
> lyrics, and dynamics.
>
>     \accidentalStyle modern-voice-cautionary

>       \partcombine \soprano \alto

One person wrote the accidental-setter to accept per-voice accounting; a 
different person wrote \partcombine.  I don't think either programmer 
considered using \partcombine with per-voice accidentals.

A lot of what \partcombine does, printing "solo" and suppressing rests during 
solos, and single-stemming unisons, does not seem to be traditional for engraving 
four-part harmony.  That makes me hope that someone has found a simpler way to combine 
two voices per staff without the complications of \partcombine.

Your method of using NullVoices to handle the Accidentals instead of the Voices 
seems like a sensible way to adapt LilyPond.  The combination of moving 
NullVoice to Staff, and changing the other Voices accordingly, could then be a 
packaged set of context definitions using the Voice building-blocks in a 
different way.