gershwin, not a bad pianist himself, would have been knocked out. ♪ ♪ ( cheers and applause ) marcusmother still lives. as a little kid, wherever there was a piano, he'd try to unlock the mystery of the keys. so his mother and his father, a longshoreman down on the jacksonville docks, scrimped and saved for that piano marcus could call his own. >> coretta roberts: he went right to it, and went to playing "mary had a little lamb." ( laughs ) >> marsalis: his mother coretta is sightless, too, blinded by glaucoma. she remembers the pain of having to leave school in the seventh grade because she couldn't see the blackboard. >> coretta roberts: it was just like i had lost a loved one or something. >> marsalis: and by the time he was five, severe cataracts blinded marcus as well. how did your parents explain your blindness to you? >> roberts: they really didn't explain it. they just taught you how to do stuff for yourself. that was the main thing. >> marsalis: marcus told me that you were never about self-pity or feeling bad about yourself. >> coretta roberts: oh, no, no. ( laughs ) i got