?

you've used rosegarden? you know the issues that it has on a standard linux kernel? (it's a genuine question)

i'm no expert in linux or audio, but i think the problem stems from the fact that linux is not an RTOS. I've used rosegarden, and their documentation recommends a real-time kernel for serious work.

(i won't run away from the possibility that rosegarden is likely bloatware anyway)

As for being old and the rest, yes, i knew all that. I even bought an old Nokia 6230i back in the days just to enjoy 64-note polyphonic MIDIs .. again .. that dumb phone is much underpowered compared to N900