Re: Easy definition of music function

[David Kastrup]

Lukas-Fabian Moser <address@hidden> writes:

> Folks,
>
> I sometimes enter music which consists of a lot of "patterns" where
> (relatively complicated) constructions of beams, tuplets etc. are used
> repeatedly with changing pitches. Of course I'd like to put those in a
> function.
>
> For instance, in a Mozart symphony I have
>
>   r16 \once \omit TupletBracket \tuplet 3/2 { c32([ e g] } c16) c-!
>
> all over the place. So, I want do define a function \pat that takes
>
> \pat c e g c
>
> and creates just this pattern.
>
> QUESTION: I am under the impression that, since I want to give only
> pitches to the function, I have to create the music in Scheme, and
> hence I do not know how to attach the various articulations etc. other
> than in Scheme. Hence, my function now reads:

[...]

> Works like a charm, but I admit that I find the definition quite
> tedious (me being a non-Schemer, essentially), especially I think that
> I only realized part of -! in my articulation definition (the MIDI
> part being omitted).
>
> What I really would like to have is something like:
>
> pat = #(define-music-function
>         (pa pb pc pd)
>         (ly:pitch? ly:pitch? ly:pitch? ly:pitch?)
>         #{
>              r16 \once \omit TupletBracket \tuplet 3/2 { #pa 32([ #pb
> #pc] } #pd 16) #pd-!
>         #}
>         )
>
> But of course this does not work since pitch #pa and 32([ do not glue
> together.
>
>
> Is there some easy way to define the function I want?

Use $pa $pb $pc (and make sure to add a space before adding something
like ] afterwards) and $pd .  For # in music expressions, Lily expects
music expressions, not pitches.  For $ it chooses the syntactical
category according to expression type.

-- 
David Kastrup