“As reclusive as he is legendary, Mr. Peterson is an artist whose amazing technical command and uncanny musical instincts have for decades instilled in other musicians the kind of awe and fear he expresses about his idol, the late Art Tatum (he once compared that piano master to a lion: an animal that scares you to death, but one you can’t resist getting close enough to hear roar). Over a decade ago, however, Mr. Peterson suffered a stroke that debilitated his left hand and left him in a weakened condition. He has been battling his way back ever since. It’s an arduous challenge.”