GAE uses sourceforge.net for hosting and tracking. The tracker is the actual schedule-thing the devs use to organize their work - tracks bug reports (called "defects"), feature requests ("enhancements"), TODOs ("tasks"), possibly more - each of these, regardless of the said type, is called a "ticket".
A query on this tracker ( http://sourceforge.net/apps/trac/glestae/query
) for summaries containing "music", ordered by milestone, gave me 2 closed tickets:
Milestone 0.3: #99 Multiple music tracks per faction
Milestone 0.3.1: #159 Shuffle option for multiple music tracks
And 3 open ones for Milestone 0.5 (note current stable GAE is 0.3.2 and there is a 0.4 beta3 out):
#187 non-faction music play-lists
#291 music play-lists per subfaction
#292 allow music play-lists defined per unit
Now don't these three sound exactly like what you want?
None of these has a "Owner" yet - not assigned to anyone yet.
So, my suggestion:
1. Signup for a free sourceforge.net account if you don't have one yet - just use the link I gave you above to find your way around.
2. Find your way to the gae-devel mailing list, introduce yourself and your intentions. - friendly list, all people who are out here in the GAE forums...
3. Through the mailing list, this very topic or the tracker interface, try to assign yourself to those tickets. I'm sure you'll have no problem at all with this.
(and though I'm no GAE dev, just a player/modder, WELCOME!