Playing MIDIs using the DMC2 object would be pretty much pointless. You'd boost your game's size for no real reason because you'll need to include bass.dll within your game and if your game happened to be commercial, you'd have to cope with the expensive license price of bass.dll.
If you have MMF 1.5, you can simply use the DirectShow object to play MIDIs. Instead of loading video files in it, you just open your MIDI file and you can play it without any loading slowdown. They even loop perfectly and you can get them to play over frames, too.