“If I want to improvise during “Mary Had a Little Lamb,” for example, first I memorize it. That’s because when I’m performing onstage, I want to let my mind be completely free. “Mary Had a Little Lamb” is there, and I can come back to it if I want, but what I’m creating is greater than the sum of the parts — technical ability, notes, themes — I’ve collected along the way. The song is in the back of my brain where many other things are stored, and in that way, it becomes just another item that I can call upon when I’m playing.” – The New York Times