Sounds like an interesting concept, rosegarden on a mobile phone. I'm
not sure what basic operating system it uses but reading the first lines
of the wiki article, if it has gcc4 and there is a way of getting the
sources into a build directory, it might very well build and work. Maemo
needs to support jack libqt4 >= 4.4.0 alsa ladspa dssi libxml2
fftw3libsamplerate libsndfile and liblo and you need the devel packages
installed before building. I will research a bit more come back to you.
I think it's at least feasable.
Regards
Dave P