metronome-mark-alignment

[Daniel Rosen]

I just rediscovered David Nalesnik's metronome-mark-alignment function in this 
thread that I originally started years ago: https://bit.ly/2QUmi6H

The function works fine as long as Metronome_mark_engraver only exists in the 
Score context. However, if it's added to, say, a Staff context or a Voice 
context, it prevents the file from compiling and yields the following error 
messages:

> ~/example.ly:23:14: In expression (ly:make-simple-closure (quasiquote #)):
> ~/example.ly:23:14: Unbound variable: ly:make-simple-closure

See the attached example.

Can anyone tweak this function so that it will work under these conditions?

DR

example.ly
Description: example.ly