Thanks for the info,

The piano roll score looks nice, is this a library object, where can I find 
this.

Those are the scalars done with data structures - so, in a way, each is an object.

Tracing data also backwards would be a solution, have to look.
Midifiles for ensemble mecanique have up to 1 million notes, so effiiency might 
be an issue.

if you want to display them, that will surely lag at least when opening the canvas. My patch has 36K scalars, I haven't opened it for a while but I think it took at least one minute to open - but after that, no more issues, also not when scrolling through it.

If you don't need a graphical display, then data structures can still be used eficiently without scalars - or [text], or [coll], etc.

Joao