Don't limit yourself.
Going back to the 60's and 70's when Guadalupe was "the drag", Austin's live music scene seems to get pigeon-holed into one strip, which it most definitely is not. Spend some time on 6th, sure, but venture out to Antone's, Threadgill's, the Broken Spoke, and the Continental Club, just to name a few. I echo all the other comments about Austin's cool, etc. just don't think 6th St. should be considered the epicenter of that.