M.G.
My daughter has been going to Music Together classes since she was about 6 months old. I believe she developed more than music appreciation in those classes. Most of the classes I've been to have mixed ages so she learns from the older kids and interacts with them. My child was a little late in crawling and walking etc but she seemed to get more motivated when she saw all the other kids moving around in the class. It's a great way to bond with your child and have some fun too. I've been to one other music class but I found this one the most organized and worth the price.
Each class has one teacher but each child has at least one parent/caretaker with them. It's a 45mins class weekly. For the cost, we got 2 cds, a book and 10 lessons.
http://www.musictogethermontgomery.com/