GBAMusRiper is a brand new utility that allows you to rip music from many commercial GBA games into a combination of MIDI (.mid) and SoundFont (.sf2) formats.
Although a few rippers already exist, this is the most complete one as it allows you to replay music that sounds exactly like the original but without emulating the GBA. RHDN Project Page
Relevant Link: (http://www.romhacking.net/utilities/881/)