The bikes are yellow here (Yellow Bike Project) but I think it’s the same deal.
I don’t think you’ll have a problem getting around downtown and the campus area (University of Texas) which are where most of the music scene is. If you want to check out the hill country or go to the lake (there are a couple venues out there) then obviously a car wouldn’t be a bad idea. The bus system isn’t especially fast, but if you’re not in a hurry it’s pretty easy to get around for cheap.
Worst case scenario you might end up taking a cab to South Congress ($10??) or something, but if you’re staying in that area a car would be a waste of cash that could be spent on burritos.