There's the legendary story of Paganini, who played a Rolla violin concerto note-perfect at sight when still very young (8 years old, it's said)...

Apparently Rolla was ill in bed and didn't want to be disturbed, but young Paganini started to play a manuscript which was lying on the table... as a result of which Rolla agreed to tutor him. One wonders why he needed tutoring if he was already that good!!