Few days ago I asked how to get the number of beats and the duration of each beat of a measure.
The reason was that I wanted to try to write some facilities to add a ticktock measure at the beginning of a score:
My idea was to transform a score like this
\version "2.19.81"music = {\time 3/4 a b c'}\score {\new Staff \music\layout {} \midi {}}
to something like this
\version "2.19.81"music = {\time 3/4 a b c'}myRests = {\time 3/4 r4 r r}ticktock = \drummode {\time 3/4 hihat bassdrum bassdrum}\score {<<\new Staff {\myRests \music}\new DrumStaff { \ticktock}>>\layout {} \midi {}}
For this I thought to write a substitution function etc. Something like this (it doesn't compile):
\version "2.19.81"myScore =#(define-void-function (music) (ly:music?)(let (myRests #{ \time 3/4 r4 r r #} ) (ticktock #{ \time 3/4 hihat bassdrum bassdrum #}))#{\score {<<\new Staff {\myRests $music}\new DrumStaff { \ticktock}>>\layout{} \midi{} } #})music = {\time 3/4 a b c'}\myScore \music
The "let" part is not correct. I don't know how to define variable containing lilypond code using let. So any suggestion is appreciated.
And of course the function should create a myRests and ticktock of the right length according to the $music contents.
Any help is appreciate.
Thank you, g.