Sharper Notes Doubles the pierce power of the guitar Cost: 100 Electric Guitar Halves the pierce power but paves the way to the amp upgrade. Cost: 500 Amp Triples the pierce power from the power that the guitar had after the sharper notes upgrade and quadruples the range Cost: 1,000 Backup Band Adds a backup band which quadruples the pierce power from the amp pierce power and adds the ability to make temporary amps which explode on the track. Cost: 10,000