MODPlay is a statically linked library for playing music in tracked music sequencer formats. The library nowadays supports MOD, S3M and XM formats.

Quote from CHN:

The MODPlay library was used in many GP32 projects, and even today, it is still part of many independent games and of the libogc library which in turn is part of devkitpro. In the meantime, I have rewritten MODPlay. It supports the MOD, S3M and XM formats now and is expandable.