Talk to her more at band rehearsal. Get to know her better, and maybe when you're more comfortable with each other you can ask for some sort of contact information-phone number, msn, etc.. If you never have the time, that's something you need to work out within your busy schedule. Talking to her here and there, when you can, might at least show her you're interested. Good luck.

Ask her if she wants to blow your flute.

He doesn't mean it like that lol

When you see her in rehearsal talk to her when you have a break. I assure you she won't think your a creep.

Yeah she won't think you're a creep unless you get too nervous or unless you stare at her jugs, but she's in band so that won't be a problem.