[__tsidewinder__]

I'm not sure if I should put this here, but ah well

How about you have the styles mentioned (blues, jazz, rock, folk, etc.) and for each, you coiuld have a sub area where members contribute cool chord progressions for that specific genre? This would be especially helpful for the jazz section, as the progressions are so hard to come up with in that area (at least for me!).

I think that you don't need to worry about keeping the music and playing styles seperate. I think that would overcomplicate things a lot.