I had previously linked it up but I went to the author's site and it seems it was updated a lot in 2010 (the last version being in late November 2010) and the last version I spoke of was probably in 2009 and the changelog was extensive so best I mention it even if I do not stick it up on the portal. People that want to know are probably aware that the DS has quite a few audio programs on the commercial side (electroplankton, band brothers and the KorgDS-10 being the most notable but things Rhythm n Notes exist along with the more shovelware side of the spectrum). The homebrew crowd is definitely no slouch here either (early 2009 vintage but a nice overview- http://remaincalm.org/index.php/ds-music-apps and http://dsmidiwifi.tobw.net/ being two good jumping off points). MeRAMAN made NDS_BGMFILER which acted as a virtual keyboard and a midi player (among a few other formats- probably have to go somewhere else for MOD and XM though). Alongside that there were various libraries that went into that for developers to use (MeRAMAN's site is probably where I would start if I was a native Japanese speaker looking to get into DS homebrew though the audio side and other stuff alone would be enough for me to suggest it to anyone looking to play in that side of things). Project homepage http://meraman.dip.jp/index.php?NDS_BGMFILER#DOWNLOAD Binary up on filetrip http://filetrip.net/nds-downloads/applications/download-ndsbgmfiler-2010-11-15-f31525.html Source should be up there shortly but my upload is awful so 40 odd megs is going to be a stretch. The changelog is quite long and in Japanese but picking out the good stuff it seems devkitPro 1.5.0 support Keyboard now scrolls (before shifting between octaves could be troublesome when playing at the same time). UI tweaks towards usability (volume control) General bugfixes big and small. Improved support for various common midi type operations (Vibrato rate among other things) More instruments (jazz drums most notable) and waves for them and existing instruments.