Lately I've been searching for a minimalist MIDI player I could quickly use to check what I'm downloading.
Most of the time, I simply use winamp, but I can't really see how the midi file looks like, how many tracks it's split into, the number of notes, or how it's going to play inside Synthesia.
The only solution is to launch a full MIDI program that will take a while to start, or to play the file inside the game.
So how about...
-Synthesia Midi Player-

Basically it would reuse the core functions of the software, in a minimal way. MIDI files are associated to that player, so that it launches instantly when double-clicking one.
You can see the full list of tracks as they appear in the game, and mute or solo each one. Also, the option box let you configure the output, so you can play the file through
your external VST. The '+' and '-' signs are here to change the volume instead of speed, along with the regular controls.
Midi hunting being one the the greatest side-hobby of Synthesia users, I think it would be nice to have something like that.