Rocker Buddy Knox's first tour was with Fats Domino. Buddy and I both stated school in Happy, Texas and became college chums (I sang in his loose-knit, campus group, "The Serenaders").
Buddy opened at New York's Paramount Thereat with Domino. His most frequent remark about Fats was, "Man, he could really sing." I got no impression that they 'hung out' or became close friends, but I know that Buddy admired him a lot.