Lulu - Where abouts are you located??

I'm a private music teacher & teach kids from 3yrs of age - There are many different things out there that would be great for him!

I teach Munchkins Music classes, which basically are a small group of toddlers (With mums, depending on their age) - and do a 40min class each week.

Although its planned out, its all very casual - We do anything from listening to music and understanding dynamics (loud & soft, fast & slow, etc) to listening to The Carnival Of The Animals and being the animals to the music - the swan, the tortoise, the lion, etc.
We also do lots of singing and playing of percussion instruments - tambourine, castenets, etc - and the kids learn the difference between music you march to and music you waltz to, etc.

From my experience, my program is very similar to most others - If you are in Sydney, the Yamaha School Of Music in Willoughby used to have a great program - I know our local conservatorium has one similar too - I think they're everywhere.

The advice I can offer you is to definately make sure the person running the course has music qualifications... The childcare to me isn't too much of an issue, as for young children, the parents usually stay, but small children with music are like sponges and just absorb everything - Thats why they are almost always brilliant with music so young.
If they absorb the wrong things music wise, it will take many yrs to pull them out of bad habits later on if they wish to pursue musical tuition when they get older - eg piano lessons, etc. (Talking from experience here - I have quite a few students who are just brilliant little musicians but have been held back from lazy tuition )

If your little man has a good ear, my advice is to get him into something now - It doesn't need to be anything structured or serious, but just has to be done by someone who knows what they're doing!!

Let me know what area you're in and I may even be able to recommend someone personally!!!!

Good Luck xx