Notice Howard Stern wondered how much of the first song was actually the boy playing.

https://tv.yahoo.com/tv-in-no-time/9-olds-dazzling-agt-debut-064035988.html

As soon as the kid started I wondered the same thing and I'm glad Howard picked up on it. Funny how it was almost anticipated that his actual playing would be questioned as he immediatly offered a second number. Great playing for such a young kid but the theatrics were a little over the top.