KazoWAR releases “NDS Music Player” in a public alpha version. It’s based on fincs’ SSEQ Player and allows to play music tracks from commercial games, while pointing at it’s ROM.

Here is more of the original message:

I added a file browser that is most likely still buggy. Browse your cart for a NDS game that uses SSEQ music. Press A to open and then it will read the SDAT data and build a list of all SSEQs in the SDAT. Browse for the SEEQ to play and press A. This is Alpha software and has not been tested for bugs. I am just excited I got it to actually play the music off the ROMs.

http://gbatemp.net/t306997-nds-music-player