Isn't it wonderful..... and the best thing is that I do this sort of stuff for a living!! I work as a Music Therapist, mostly in a Hospital setting now, but have worked with all populations of special needs individuals.. You can find a past discussion here on music therapy.
I have seen many, many times in my work where music becomes the motivation factor in someone's life and has provided the catalyst to make a change in their life. As Clive Robbins states (a giant in the Music therapy field): "Music cannot normalize, but what we can do is reach that part of the child (individual) and help them to unfold a be a part of the world around them" We can use music to teach physical skills, social skills, communication skills..... it can be used for emotional expression (we do that all the time, right?) and a myrid of other things as well.

I've seen kids 2-3 years old try movements they've never done before while their moms watch with eyes wide open, because they like the sound of the music..... motivation!!

Keep up the good work, Marion. There is lots of information out there to help as well. Check with your local library or university music dept for journals/books on Music therapy. There is a big rescource there to be used....

Musicman