Jim ported MikMod a program which plays various module formats over to the PSP. Thanks to self0 for the news. Author notes:

I’ve ported MikMod module player V3.0.3 to PSP. I think this about the last version released before the player GUI was split from the actual player, c1999. I can’t find any current maintainer to submit changes to. It will play most MOD, XM, IT, S3M, STM, MTM, 669, FAR, DSM, MED, ULT and UNI tracker files (while other things are happening). An example app is included. I built it with cygwin and beta 1.0 SDK. The modules I used are hardcoded in the source.

http://forums.ps2dev.org/viewtopic.php?t=2540