I ran into this recently, and have to share it with you guys. Someone arranged various piece of music (MIDI format) to include "pictures" when played in this program. The results are completely mindblowing. Examples from the page: http://www.youtube.com/watch?v=-wkI7hg65F0 http://www.youtube.com/watch?v=ASXnFRYf6LI I've played several pieces of music from my MIDI library using this program and I actually had to snap myself out of the trance every minute or so. It's that mesmerizing. You should try it if you have the chance.
Here's one made with Renoise (www.renoise.com) by a cyber-friend of mine; Alexstrain http://www.youtube.com/watch?v=tp_5tfcD2KE
It plays MIDI files so you have to search for midi files (.mid) If you download then put them in a folder you will remember.
The player reads MIDI-format sound, although you won't see "pictures" on files other than ones specifically written to have pictures. The player I linked to has a couple of files that you can play to test it out, you open the file and then press the space bar. If you want to try other music, try this site. It has tons of MIDI files of game music, arranged by fans.