I want to include a change of midi tempo at various points in a score, using something like \setSpeed #2 #120
where setSpeed = #(define-music-function (parser location scale speed) (number? number? ) #{ \set Score.tempoHideNote = ##t \tempo scale = speed #} ) I'm still using 2.18 I'm afraid, which still used the parser and location parameters.. I'm assuming this should be a music function rather than markup, but perhaps my arguments aren't numbers. In this case the function is hardly worth it, but I want to base more complicated routines on it, and have failed at the first hurdle! Jonathan