So both these courses are open right now so i'd appreciate any quick help
Im trying to decide between Econ 1B03 and Music 1AA3, i've never taken any classes in Econ (because I dropped it in HS since my teacher was such a bore -.-) but I heard that for the music exam the professor plays like a sample of music and we have to tell who the composer is and everything, im not sure if I would do that well in this :/ any thoughts?

Depends what you want. Both classes are fairly easy.

If it were up to me, I would pick Music 1AA3. I've taken Econ 1b03, and it's boring.