KazoWAR updated “NDS Music Player”. It’s based on fincs’ SSEQ Player and allows to play music tracks from commercial games with a GUI browser pointing at the desired ROM file.

NDS Music Player Update
Watch this video on YouTube.

Changes:

-- Automatic play mode added. Push select to enable/disable it.
-- Track Fadeout option added. Push Y to make it happen. (Will also happen in auto-play mode after 2 loops of a given sequence.)
-- File names with special characters, like Pokémon, no longer cause problems for SPS Maker.
-- Pause mode added. Push Start to pause/resume a given sequence.

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