Best tip for this mission is to protect your roadies!
Use the new Glitterfists' combo move to piledrive oncoming enemies. And once you got your speakers, combo a roadie to ride out in epic blasting style.
Stay in your group and blast seagulls when they start to gather. (I didn't have the seagulls gather enough to see what they do, but considering Ophelia's warning, best to be safe. ;p) Only go ahead to blast the last group of enemies.
Once you get back to the bus, you'll earn your French Kiss degree with flying colors. Go, RIggs!