The anonymous sleeve notes on the 1960 RCA Victor album "Handful of Keys" state that Waller copyrighted over 400 songs, many of them co-written with his closest collaborator, Andy Razaf. Razaf described his partner as "the soul of melody...a man who made the piano sing...both big in body and in mind... known for his generosity... a bubbling bundle of joy". In the same notes are comments by clarinetist Gene Sedric, who recorded with Waller in the 1930s. "Fats was the most relaxed man I ever saw in a studio, and so he made everybody else relaxed. After a balance had been taken, we'd just need one take to make a side, unless it was a kind of difficult number."