Another perspective: we left a music class for 4-5 year olds that DS had loved because two musically gifted kids entered his class as 2.5 year olds. When their parents could get them to fully participate, yeah, I could see why they wanted to be there instead of the 2-3 class. However, these kids were 2, and very much 2 in following directions, gross motor skills, and paying attention skills.
For a lot of these classes, there's more to the class than the advertised content. These secondary skills don't always develop alongside the development of the talents. Often these have consequences for the other kids in the class. I was really sympathetic to their situation, but they were not only disruptive to the class, but my son didn't get the same peer-to-peer interaction that we were seeking in through the class experience.
Instead, we've aimed for classes where my kids are at the lower end of the age range or are targetted for a very broad range of kids or are leveled (like swim lessons). This stuff gets easier as the kids get a bit older.
