<font size='+8'>Cities and Fans</font>
You may have noticed that at (almost) every show you perform you will earn some new fans. Most of these fans are probably from the city you're playing in, but it's likely that a few have also visited from nearby cities. Impress them, and they'll go home to their cities and tell their friends about you. With a little luck, you'll be invited to play a show at a small venue in that city. Play there, and people from other cities close to the new one may visit and see your band play. And the cycle continues.
Because of this, you'll unlock cities as you play shows close to them. You'll expand ever outward from your hometown as your fame grows. Your 'rock empire' will grow in the direction you choose to travel and perform shows.