Artsy neighborhood in Barcelona Spain?

Going to Barcelona this summer. Dont care to see all the tourist attractions, but want to live like a local for the 2 weeks that i will be there... I was wondering where is the arty side of Barcelona. i know its all really artsy and creative, BUUUUUUTTTT what about the underground stuff! the things the locals will do. and for the artsy locals what side of town do they live in! What neighborhood? for the most part.