Fats Waller (1904-1943) was an outsize man in all respects: five feet, eleven inches tall, he weighed 285 pounds. The greatest of the Harlem "stride" pianists, he composed hundreds of songs, he led a band that made over 400 recordings, and he wrote several Broadway shows. Waller's gargantuan appetites have been celebrated in anecdotes and earlier biographies. He is seen by jazz historians as a man of immense musical talent that was never fulfilled...