I'm working on this, as well.
Though, for me, MIDI is of much greater interest; since I can play MIDI on a variety of non-computer devices as well. (midi files are smaller than MOD too, although soft synth is more cpu intensive on the Zaurus...)
With some limited success,
I've tried:
jazz
jazz++
cantor
shaketracker
tektracker
seq24
midimountain
muse
rosegarden
Cantor, MidiMountain, ShakeTracer and Muse- I can't get to build properly at all.
Most rely on ancient libraries, or compiler versions.
Jazz (old) can't build, because I can't get the (old) wxwindows library (dependency) built to begin with.
seq24 builds, runs, but bails out with segfaults soon after launch. The GUI doesn't look pretty, but may be useable, if fixed. (it also complains about missing a hardware /dev/sequencer . I'm unsure if this a fatal error, due to subsequent segfault)
Tektracker seems to freeze when opening/saving files; it's possible I may have been doing something wrong, but the gui is somewhat wonky (its using curses)
Rosegarden is bug-ugly, and too big for 640x480, much less 240x320.
It appears to be fully functional, but crashes often. Worse, the widgets are too
small to see and manipulate on a Zaurus screen...
I get the feeling it was designed for 1024x768 at 21"
Jazz++ lacks a score editor, but otherwise seems adequate to the task. The GUI is fine, on 640x480, and windows can be tamed to fit (maybe 240x320 even)
The major problem, so far unresolved, is an issue of memory alignment/endianness
when loading/saving. File opening works, with some corruption; File save simply segfaults. I've been poring over the code trying to spot the problem and fix it,
but so far haven't had much luck. If any forum lurkers have experience with
endian/alignment matters, and could shed some insight, or enlightenment, I'd love to hear from you, or work with you on this problem.
So, for MIDI, no go, this far in
worse, most of the ones I've tried seem to be long, long out of development.
TekTracker may be viable (it requires some dependencies that aren't likely to be in your SDK- build them, or find an ipk) but I don't really use trackers. It also could have alignment issues; I really don't know.
Rosegarden is useable if you're desperate, but I found it just too annoying.
Jazz++ looks like it needs some help (maybe not too much more!)
All this in X; but ttrk doesn't need graphics, and some of the others may work in QT as well.
http://vektor.ca/audio/ttrk/http://www.rosegardenmusic.com/http://jazzplusplus.sourceforge.net/
