Actually Jack is REALLY into the happy sounds of Jean Jacques Perrey . . which is cool as JJ is a family friend and you couldn't find a bigger moog head the JJP.
My other boy, Noah (2) is more of a digital kid . . Jack will open the filter wide and go whacky with the modulation where as Noah likes the sharper bell sounds . . and he likes the BIG alpha dial on most digital synths (although he does go crazy for the dial on my moog Source).
We are a big musical family so no doubt the kids will be into it . . just got to stear them in the right (moog) direction.
Mal