I have tried Audio Compositor, and it
looks promising. It can load soundfont
files, and even load a Midi file to play
the soundfonts. However, I am getting
some distortion(could be because it is
the demo version)and CPU overload.
You can make custom scales, name, and save
them. However, I've noticed that it affects
every Midi channel including ch.10 for
drums. I guess it is acceptable if you
you don't care that some drum sounds are
slightly detuned based on the active
scale. Has anyone else tried this program
yet?