Use the Triangle button but make sure the controller is plugged into the first
Unlock Track 21-25
Complete tracks 1-20 all the way through in any mode.
Unlock Songs 23-28 (US Version Only)
Complete the first 23 songs on any difficulty.
Unlock Master Level Difficulty
To unlock as master difficulty, get an A in one of the tracks. You will then have
a new difficulty level. It is virtually identical to the hard mode but with less
warning when the heads will appear.