This vocal quartet originally started life as an extension of jazz band the Hi-Lo’s. From that prominent '50s band came Don Shelton, who decided to form Singers Unlimited after the Hi-Lo’s broke up in 1964. After retreating to Chicago, Illinois, where he worked on a series of television commercials, he enlisted fellow Hi-Lo’s veteran Gene Puerling of Milwaukee, Wisconsin, to join him in the city in 1967. The group was formed along with Len Dresslar and Bonnie Herman, with the express intention of recording commercials in the doo wop/vocal group idiom. Shelton’s connections in the industry ensured the group was able to exploit the market successfully, and lucrative work rolled in. However, the 30-second snatches of songs hardly satisfied their artistic ambitions, and when they found themselves with studio time left over after one session, they recorded a take on the Beatles' "The Fool on the Hill." Through visiting jazz pianist Oscar Peterson, the demo of the a cappella recording was passed to MPS Records in Germany.