Re: Part combiner: separate split state and voice names

[Keith OHara]

Dan Eble <dan <at> faithful.be> writes:

> I would like to break the rigid link between the split states 
> (apart, unisilence, etc.) and the names of the
> voices into which the Part_combine_iterator routes events.  

The patch back at
http://lists.gnu.org/archive/html/lilypond-devel/2008-09/msg00079.html
makes sense, and seems flexible enough.  The awkward part was naming
the Voice contexts for the four states of music.  Given that you need
that information in the output of \partcombine
     pc = \displayMusic \partcombine {b2 b ...} {b2 b ...}
for the iterator to see, it seems that music properties are the only
places to put it. Maybe one property that takes the full list of context
names...

> I would like the Scheme portion of the part
> combiner to dictate the names of the voices to use at every moment. 

Simply letting us specify the Voices _once_ for the whole output of
\partcombine would help a lot.

Include an example in your patch, where we want to rearrange the routing
of soloI, unison, etc., to Voices mid-piece.

The example in the 2008 thread, setting unison directions, is better done
with \context Voice="shared" {\voiceOne} than by changing Voices.

The first use I can imagine is that I would usually want the shared Voice
to be identical with the first-part Voice, but sometimes would want the
shared events to go to the second-part Voice.  In that case, I am thinking
of the Voice output arrangement all at once, so specifying a list of four
is natural.