Screw it. I'll post my ideas anyway. There's no way I can do them all.
Code name RoomDrum: Turn your room into a drum set with effects processing. Map things in your room by drawing a polygon overlaying a display of your room, to sounds that can be played by percussive motion. Sample sounds from, say, the couch cushion, amplifying them and adding effects to the sound, thus building up your own unique set of samples from your environment. Then drum away on whatever you want ... glasses, table tops, remote controls ... whatever ... add loops and effects as you go. Difficulty: Can the Kinect track drum sticks? What about speed of the sticks? If not, we can just use hands. Additional features: Map scales to areas ... either the entire range of notes broken down into intervals of adjustable size and shape (i.e. in a polygon overlaying whatever region of the room, divide the polygon into intervals), or choose specific scales (i.e. pentatonic, enigmatic, whatever) and keys.
This one I'd really like to make.
Yes, W3bbo, I know there are lots of Kinect music sample/POCs/demos. However, the one in my head is awesome!