As far as most world class classical concert pianists are concerned, most of them were probably prodogies and most started playing 5 years old or younger, Argerich, Perahia, Serkin, Rubinstein, Hofman, Kissin, Lang Lang are examples. A few started serious study later (Richter for one even though he played from a young age) and to me THESE are the one's that are true prodigies, a difficult instrument to start late on and become a world class musician.
How about Red Garland, started playing at 17 years old.
How about Red Garland, started playing at 17 years old.