Re: multi-instrument parts

[Keith OHara]

On Tue, 15 Jan 2013 19:41:00 -0800, Kieren MacMillan <address@hidden> wrote:
> Boo. I really wish Lily would Do The Right Thing™ with regard to transposing 
> parts. I want [...]
>  perhaps I'll put together an official feature request…

Almost certainly, \instrumentSwitch was written in response to a similar 
request.
The basic Lilypond structures can do quite a lot by themselves, see below.

> It would help immensely if I could at least say
>    \tag #'part { \transpose c d }
>    c4 d e f
> and then use the tag filter to leave the transposition out of the C-score

In LilyPond \transpose c d {...}  is an action, acting immediately on the music 
in {...}
LilyPond does not store the name of the action separately from the music it is 
acting upon, so it does not provide a way to remove the action and leave the 
music.

But you can store the music in a variable, and perform the action of 
transposing only where you need it.

music = \relative c' {
  \transposition c
  \key bes \major
  bes4 c d es }

clar = \music
flute = \music  % A bit silly, but everything is clear if they play in unison

\new Staff { \flute } % Flute part
\new Staff { \transpose bes c' { \clar } } % Clarinet part, transpose for 
printing

\score {  % Score in Concert Pitch
<< \new Staff \flute
   \new Staff \clar >> }


You might see that people often define their variables to store the music in 
pitches as-written for the different instruments.  The manuals encourage 
storing music in concert pitch, though, which is probably less confusing, at 
least until you have used LilyPond for a while.