Re: \transpose not work working inside define-music-function

[Wols Lists]

On 27/12/15 16:32, J Smith wrote:
> I'm trying to define a music function that transposes a chord and a 
> melody multiple times.  But for some reason, the transposition is done 
> only once.
>  
> Here's my attempt:
>  
> repeatpattern =
> #(define-music-function (parser location chord pattern) (ly:music? 
> ly:music?)
>   #{
>   % <<
>   \new ChordNames {
>     \transpose c d { #chord }
>     \transpose c e { #chord }
>   }
>   \new Staff {
>     \transpose c d { #pattern }
>     \transpose c e { #pattern }
>   }
>   % >>
>   #})
>  
> \score {
>   \repeatpattern { c1 } { c'4 d' e' r }
> }
>  
> (delete the %'s preceding << and >>; had to add them to pass Gmane's 
> filter).
> 
> Any ideas for why this is not working and how to fix it? (i.e., it 
> should transpose "c d e" into "d e f#" and "e f# g#", not into "f# g# 
> a#").
> 
Just a guess, but \transpose is funny - I think of it as taking note
NAMES. As soon as you've fed the names through anything (such as
define-music-function) they've been converted to note PITCHES, and
\transpose no longer works.

Short answer - \transpose is very temperamental and sensitive as to
where it is used.

(And note, my understanding is almost certainly technically wrong, I
just find it helpful as a superficial guide to what's going on.)

Cheers,
Wol