Music Therapy with a young boy with autism

I recently went to see a young boy with autism at his home.  When I got there, I could hear him screaming when I was outside the door.  When they opened the door, it was clear he was upset.  He was wondering around, screaming asking for things, but not really wanting what he was asking for because when his mom would give it to hm he would just scream and ask for something else.

The mom looked at me and said, "go ahead and see what you can do."  I took out my guitar and strummed a chord.  The boy stopped.  He looked at me.  He came over and we sang and played instruments.  It doesn't always work that quickly and dramatically, but it has worked like that enough that I wasn't surprised.