Cain was born in Philadelphia, Pennsylvania, United States.[2] Growing up, he befriended two brothers, Wilbert and William Hart.[4] During their attendance at Overbrook High School, Cain joined the Harts' existing vocal group, when a couple of its members dropped out.[5]
Cain left The Delfonics in 1971, with singer Major Harris taking his place in the line-up.[5][6] In 1973, while working for recording company WMOT Records, Cain helped introduce singer-songwriter Ted Mills to the vocal group Shades of Love, which Mills would join to form Blue Magic.[5]