Re: Add chord range to make-part-combine-music (issue 144170043 by address@hidden)

[Keith OHara]

On Fri, 07 Nov 2014 04:37:41 -0800, <address@hidden> wrote:

> On 2014/11/06 05:44:50, Keith wrote:
> > Changing the current global variable 'partcombine-chord-range' will
> not become
> > the user interface.
>
> All I meant for that variable was to avoid repeating the same magic
> numbers three times.  Is there a more idiomatic way to do that in
> Scheme?  Should I have commented it?

No, that seems fine as it is.
I was trying to go through the possible user-interfaces systematically, and 
exposing that global variable was one possible interface.  I had trouble 
articulating exactly /why/ simply changing that global variable wouldn't become 
the user-interface.

I forgot the originally-suggested possible interface for the user to change the 
chord-range, by setting some context property of the temporary Voice contexts, 
the ones used by \partcombine to iterate through its inputs.  Then we could 
change chord-range in the middle of the music, but I'm not sure the 
\partcombine logic can handle mid-music changes.  The analysis is global, so if 
you double-stem the e' below, probably the slurs should separate and all 
slurred become double-stemmed (like \partcombine already does if there is a 
voice-crossing).
  \partcombine
   {e'( e' b' f')}
   {c'( e' g' c')}
Changing chord-range just before the e' might (or might not) fool \partcombine.