Re: Staff change in piano music - a general approach?

[Keith OHara]

Tobias Braun <tobias <at> braun-oberkochen.de> writes:
> 
> I've been experimenting with the \partcombine command, which looks like it's 
> made to do exactly what I want.
 
Tobias,
\partcombine is primarily for orchestral scores, with two instruments sharing a 
staff.  Lilypond tries to determine when the two lines of music share the same 
rhythm, so they they may be placed on common stems (merged into a single Voice, 
in Lilypond terminology).  But she is not yet smart enough to do that job in a 
completely satisfying way.  Automatic combining of three lines of music is a 
much more difficult job.

I recommend you do  not  use \partcombine when you have three voices, because 
the way that function combines two of the voices automatically will get in your 
way as you try to place the third voice.

The approach you have in the lilypond code you posted so far is probably best.  
You can define a short word, such as \lu, to put before individual notes to 
tell Lilypond she may let notes combine just for the moment:
lu = \once\override NoteColumn #'ignore-collision = ##t
But as you have seen, this does not tell her to combine the stems; the notes 
must be in the same voice for that.  You have to \shiftOnn or force-hshift to 
separate the stems in those cases.

Eventually, if you are really interested in using Lilypond to do this in an 
elegant way, you could investigate \addQuote and \quoteDuring.  Then you might 
set up two voices in each staff, and find a nice way to quote segments of your 
S A T B parts into those voices, so that parts share a voice during the times 
they share the same rhythm.