What American singer born in 1931 was managed by Allen Klein? 
Allen Klein:  He first scored massive monetary and contractual windfalls for Buddy Knox and Jimmy Bowen, one-hit rockabillies of the late 1950s, then parlayed his early successes into a position managing Sam Cooke, and eventually managed the Beatles and the Rolling Stones simultaneously, along with many other artists, becoming one of the most powerful individuals in the music industry during his era. Sam Cooke: Samuel Dale "Sam" Cook (January 22, 1931 – December 11, 1964), was an American singer, songwriter, and entrepreneur.
Sam Cooke