Pop 'n Music

Secret J-R&B Song:
Go to the title screen and press the following button combination:
B, Y, Y, Down, R, Y, Up, Left, Left + Start

Secret Lounge song:
Go to the title screen and press the following button combination:
Left, Up, Left, Up, Left, Up, Left, Up, Y, Start

Additional secret songs:
Play with the game to the indicated amount hour to unlock addtional
song types:

Cute: 2 hours
New Fork: 2.5 hours
Sexy Girls: 3 hours
J. Garage Pop: 5 hours
Lounge: 4.5 hours
J-R&B: 4 hours
Akiba: 6 hours
Live: 6.5 hours

Change the color of costume:
Press X

Unlock Survival and Rally mode and 5 or 7 buttons option:
Play with the game at least 5 hour