I'm not sure if this issue has been addressed yet...
I think what the community needs to help clean up the garbage and flaming is more moderators. As it stands, 5 moderators for hundreds of posters in thousands of topics is quite lacking. More members who understand the rules should be on hand to move threads to proper locations, assist confused users, and nip flaming in the bum before it gets out of hand. I have some moderating experience myself and would be willing to volunteer my time to help sort through the garbage and address meaningful posters.
Another suggestion to help improve the Ultimate Setlist forum, try implementing sub forums to help alleviate the overflow of topics. Try to use several sub forums for each genre to help people gather effective discussion on a certain band or song. I believe this one has already been mentioned, but it bears repeating as it should help organize the forums.
I realize you must have a lot on your plates at this time (being such an awesome company), but I hope you take my suggestions into consideration.