I did this YouTube video, My Kids Meet WolframTones, about a year ago and it never occurred to me to blog it. But now that everyone is covering their blogs with YouTube videos, perhaps it's time.
Here's what I said about it last fall:
After dinner this evening, I sat my son Peter, who has just started 3rd grade, down at my computer and let him play with Wolfram Tones for the first time. The first interesting thing that happened was that my daughter Elizabeth, who turns 3 in October, started jamming to the WolframTones soundtrack on the toy piano in the living room. (I had gotten the video camera out to film Peter, and she started while I was getting set up.)
After about 10 minutes of fiddling, Peter came up with something he really liked.