I have several autistic children in my pediatric practice, and would be very interested in what you folks have found that has helped. We're a small rural island with not a lot of local resources, but if there are online resources that have been helpful I'd appreciate knowing about them. I've helped parents work through lots of standard and very nonstandard kinds of treatment, but as you well know, this is a very individualized disorder with no magic bullet.
And Christine, to answer your original question, you might think about looking for videotapes of some traditional folk performers in concert. I'm thinking of The Weavers, Pete Seeger (alone), early Joan Baez, etc. It's not what we would think of as "kids video", but there's a reason why these old songs have been so popular for so long even without "kidifying" them. I'm guessing that your student is at a high enough level to appreciate the music. Another source is the Wee Sing series, put together by two women in Oregon whose names I can't recall at the moment. The original audiotape series includes one called "Wee Sing Fun and Folk" which is an outstanding collection of traditional folk songs done by people who really enjoy what they're singing, and I think they may have a video series now. Good luck, and welcome to the Mudcat.

Aloha,
Mark