HELP!!! what to wear??!?

ok. my boyfriend is making me go to this foo fighters concert tomorrow.. the thing is im not exactly very into hard rock and i dont know what to wear!!!! tomorrow is gonna be sunny around 22C degrees and its gonna be a out door concert.. should i wear a blouse + white jeans + black converse or blouse+shorts+convers or flats? or would that make me look too much of an outsider?