Music as therapy?

I found, and bid on, a small guitar on ebay. This is for C who loves music in his therapy sessions. I have really enjoyed being able to use my guitar with him, and he really seems to like it too. He will strum along while I change chords, or requests his favourite song "Yellow Submarine". I have been able to introduce a few new songs to expand the repertoire. I especially love "If you're happy and you know it ............" It feels like a really natural way to encourage his imitating actions, and also participating with me. Since we started using you tube videos of the wiggles as a reinforcer, he is rewarding us with great compliance, and demonstrated his ability to match all manner of cards. It has been a great way of probing which skills he chooses not to show, and which he really does not have a grasp of yet. I also found a heap of photos on Friday, of his family. He easily names all the people in the shots. If he is distracted he still names just anybody, but once he realises he needs to pay attention to get the reinforcer, he is 100%. However with a plate of bacon and eggs (of which the bacon is his favourite) he still says eggs, while looking at, and reaching towards the bacon. By the end of a plate, where he only got the food he said the name of, he was saying bacon. The test is whether he will remember this next time I have a plate of bacon and eggs to offer. He seems to study like I did with maths at school. Learn enough to pass for the semester, then forget it all once it is no longer a test subject. So we need to make sure we are teaching relevant tasks to him. Not just what we think is important. I must remember to have a go at things like his phone number, which he was doing very well at, not to long ago. Nothing on his program is very difficult for him, since we are focussing on getting him follow instructions when asked, without having tantrums. Once he gives up the control struggle, we can add some more challenge back in. I think it is a good strategy, especially since both his other therapist and myself, have only been with him a short time. Hopefully I have time to pick up the guitar tomorrow. I have a birthday party for my niece, and the guitar is further away than I had thought.