Gene Puerling and Don Shelton had formed part of Puerling's successful all-male vocal group, The Hi-Lo's, some years previously, though Shelton was a 1959 replacement for original HiLo Bob Strassen. The Singers Unlimited group were originally formed to record for commercials in the USA, but as time passed, they were persuaded to enter the recording studio to record a series of albums. On the recommendation of pianist Oscar Peterson (who was also signed to the label at the time), they gained a contract with German label MPS. They recorded two albums in 1971, the first a cappella, the second, In Tune with Peterson's then-current trio.