Re: Issue 1321: Enhancement: add partcombineUp and partcombineDown functions (issue 13242056)

[nine . fierce . ballads]

https://codereview.appspot.com/13242056/diff/26001/ly/music-functions-init.ly
File ly/music-functions-init.ly (right):

https://codereview.appspot.com/13242056/diff/26001/ly/music-functions-init.ly#newcode1168
ly/music-functions-init.ly:1168: #{ \partcombine \with { \voiceOne }
\with { \voiceOne } #part1
In one way, this is cleaner than what I currently have to do to modify
one/share/two context properties.  (That is refer to the voice contexts
in parallel with \partcombine and set their properties.)  One thing I
like about this is that I don't have to rely on the names of the voices
that \partcombine creates.  One thing I don't like about it is that I'll
have to consult the manual to check which context mods apply to "shared"
and which apply to all.  I see nothing mnemonic about their position.

In short, this is nice, but not clearly better than the status quo,
unless there is something I'm missing.

Stepping back, for the \partcombineUp use case, I think it would make
more sense for the partcombiner to distribute the input notes into just
two voices instead of three.  Rather than putting notes into Voices
"one" and "shared" that need to be configured separately with the same
context properties, just direct all top-part notes into "shared" and
never into "one."  That also has a chance of making some things that
would use or iterate over that voice work better.  Lyrics come to mind,
though NullVoice is a good workaround nowadays.  I *think* it would
improve the outcome of automatic beaming, but let me find an example
before you assume that I know what I'm talking about.

https://codereview.appspot.com/13242056/