Rock Band has one major difference from other music games: it's not about one person's experience. This is a group effort and the gameplay is geared towards teamwork. While the four members of your band must all be concerned with their own performances, you must work together to earn epic scores in Rock Band. Each instrument comes with its own Overdrive (AKA Star Power) system. Individually, they kick in a x2 multiplier for the player who enters Overdrive. But you can stack other member's Overdrives to creative massive multipliers for the entire group. Get all four members in Overdrive at the same time for a bonus x8. To do this, though, requires communication with your other team members.