In his early career Major Harris sang with groups such as The Charmers, The Teenagers, The Jarmels, and Nat Turner's Rebellion, and recorded a few solo 7" records on Laurie and Okeh labels.

In the early 1970s he took over for Randy Cain as a member of The Delfonics; he quit the group to go solo in 1974. Signing with Atlantic Records, Harris scored a string of R&B hits in the U.S., including the Top Ten single "Love Won't Let Me Wait.“

When his success as a soloist subsided, Harris returned to the Delfonics, and continued to tour with one of two touring ensembles that used the name in the 1990s and 2000s. Major is a cousin to the late Philly producer and arranger Norman Harris.