It's kind of a Musical Doodling Toy.... I played an NDS app called AXE, and was inspired to create my own similar thing for the Wii.
You just point One or Two Wiimotes at the screen, and "Paint Music."
Button B = Normal Pitch
Button A = Higher Pitch
Buttons -/+ will change your Instrument
Buttons 1/2 will change the DrumTrack
Any number of people can participate!
One person can use 1 or 2 Wiimotes at the same time (dual-wielding!).
Or Two people can each use 1 Wiimote.
Or 3+ people can sit and watch and say, "Hey, it's my turn!!" while the first two people have fun....