Looks like GS Player (found here:
http://hp.vector.co.jp/authors/VA032810/ ) has been updated at least as of Mar 2005. I didn't know until today that it could (with the help of a plugin) play MIDI files,...
I will load that snapin and see just how well it does. Thought I'd let you all know.
It doesn't have very many skins available for it, but it is skinnable. Anyone with graphics skills want to take on THAT challenge? GS Player seems to be pretty tight and stable, with features that rival that of much more expensive media players on the PPC platform.