This mean’s more than just what type of music you’ll be playing. You’ve got to decide how many people to have in your band. Are you a power trio, an orchestra or simply a DJ with a sampling program? Will you have 4 guitarists, an oboe player and a drummer? Once you’ve determined the band’s personnel/overall makeup you’ll need to decide what kind of music will they be playing. I realize that many bands dabble in a variety of musical styles, but pick one to start with, you can always experiment with their fake “sound” later.