For the 9 years old kid he was when he started playing, I thought that a 30" scale is long enough. I figured, with the violin family, young kids start with 1/4 or 1/2 size instruments. But you may be right, nofi, I don't know, your post makes sense to me. And kids start learning piano at 4 or 5 and you have never heard of a 3/4 size piano. Anyway at 11 years old my son feels equally comfortable (or uncomfortable, depending on the exercise) on a 30" Mustang, 33" Ric and 34" Fender.
When he started I showed him simple riffs around the lower frets of the E string, because that's how I was taught. I found it interesting that his upright bass teacher started him with D major and minor scales at "frets" 7, 8 and 9, and open G and D - where he can play (almost) accurately with his small hands.
