Windows Media [...] doesn't read midi
It sure does. Drag any midi file and drop it on to any Windows Media Player.
This works for Win 3.1's mplayer right up through XP's Media Player 11.
My experience is that when Media Player 6.4 is
playing a midi file, moving the volume slider also moves the midi volume slider (sndvol32), but moving the midi slider does not move MP's slider. Sometimes the midi volume is restored on exit, sometimes not. Can't speak for VISTA.
Media Player 9, does the same,
except that if you
pause the midi, the volume is set to zero! If you exit, it remains at zero.
Media Player 10 (on XP) was also altering the midi volume.
Media Player 11
seems to be better behaved. (someone must have complained) is just as bad.
The old media players (mplayer, mplay32), do not alter volume on play, pause, stop or exit.
Their menu option for volume simply launches
yet another instance of sndvol32, which is quite stupid.
All in all, I'm associating midi files with mplay32. I'll write some scripts to deal with multiple instances.
BTW, if using XP, Running this:
control mmsys.cpl,,2
puts most of what you need for midi, a click or two away.