I used this way long ago. It's got a strange layout, but once you get used to it it's not terrible. Does lack some stuff I now find important but it's not all bad.

and while on the subject of lesser known gba music programs that i never really got around to fully checking out: there's also Ditty Editor for GBA
http://www.pouet.net/prod.php?which=31794 (i might have this and boyscout mixed up in my head)

i checked it out a ways back, kind of a weird interface, and only four channels i think

http://www.pidelipom.com/boyscout/

Never heard about before and throwing here to see some responses.