This guide was written back in 2008 and it covers my various methods to extract and then convert the MIDI-based (created using Nitro Tracker) music files found inside Nintendo DS games to work with the Open ModPlug Tracker. They could then be pared back (removing unused samples and patterns) and then converted into Impulse Tracker .IT files. These could, in theory, be used elsewhere by other composers for remixed and such like.
I used to post the current ones on the old EmuParadise forum back in the day. However, after EmuParadise was closed down due to offering NDS ROMs (summer 2018), all of my music rips that you could download went offline at the same time.
I still have copies of the numerous rips / conversions that I did, but it’s just too much hassle to re-upload them all and, probably, have a take-down request appear shortly afterwards!
The guide (written in 2010) also covers the extraction and conversion of music streams from their NDS format(s) into “standard” .WAV format using the tools available back in the day. Things have moved on since, especially as Open ModPlug Tracker has moved on from the old Impulse Tracker format, so the guide could do with an update. But as with everything else on this site, it’s as an when I have the spare time.