I think it's because girls realize you have a talent and you can express it at your full potential, and that's great. A lot of girls are drawn to guys who have a talent they can express, whether it be in church or in you garage with your band. Music is big these days. Almost every person I know to be in a local band or garage band has a girlfriend. Music and talent attracts girls to guys and vice versa (Guys to some girls).
Sure some girls like to feel and look important, but I know a lot of people who were in a band and not anymore, and they're still together with his or her gf/bf.