Turning the volume down on the Wiimote allows you to focus more on the gameplay without the clicking sound.
By beating each character's story mode you unlock an additional song for both karaoke and dance mode. Beat all 5 stories to unlock a hidden stage.
Song- Boogie Oogie Oogie Beat Bubba's story
Song- Dancing in the Street Beat Julius' story
Song- Love Shack Beat Lea's story
Song- SOS (Rescue Me) Beat Jet's story
Song- Tu y Yo Beat Kato's story
Stage- Big Dub Hustle Club Beat all 5 stories