Brothers William and Wilbert Hart formed the group with Randy (Rudy) Cain in high school in the early 1960s, eventually becoming known throughout the Philadelphia area by the mid-'60s and signing with Cameo Records. At Cameo, producer Stan Watson introduced them to producer Thom Bell, then working with Chubby Checker. The group's first album, released on Watson's own Philly Groove record label, featured the smash hit 'La-La (Means I Love You)' in 1968. Four more Bell-produced albums appeared in the next few years: The Sexy Sound of Soul, The Delfonics Super Hits, The Delfonics and Tell Me This Is a Dream. Among the Delfonics' popular hits were the Grammy-winning 'Didn't I (Blow Your Mind This Time)', '(For the Love) I Gave to You', 'Ready or Not Here I Come (Can't Hide from Love)' and 'Hey Love'. Prior to the release of 'La-La (Means I Love You)', they had a hit with 'He Don't Really Love You' on the small Moonshot record label in 1966.
Randy Cain left the group in 1971 and in 1973 had a hand in formulating Blue Magic, best known for their classic 'Sideshow', when he brought singer-songwriter Ted Mills in to do some writing for WMOT (We Men of Talent), and the remaining future members of Blue Magic came in for an audition. Cain was replaced by Major Harris; by then, however, Thom Bell had moved on to produce the Stylistics and later, the Spinners, all artists in the mold of the Delfonics. The Delfonics swiftly produced another album, Alive and Kicking, produced by Stan Watson. However, in the absence of Thom Bell, the Delfonics' career declined sharply, and with the exception of the aforementioned 'Hey Love' and the minor hits 'When You Get Right Down to It', 'I Don't Want to Make You Wait' and 'I Told You So', success eluded them after 1975. '(For the Love) I Gave to You', although popular, was never released as a single. Most of their songs at this point were written by lead singer William Hart.
Lineups would become confusing as members shifted between groups and multiple groups toured. Major Harris moved to William's group around 1980, with their third member being the returning Randy Cain. Frank Washington also switched from Wilbert's group, joining in 1985.
The groups reorganised in the late 1990s. William Hart started touring with Johnny Johnson and Garfield Fleming; this group recorded as the Delfonics. Major Harris toured with Frank Washington and Pat Palmer. Wilbert also led a Delfonics group; members in the 1990s included Dr Sallam Love (formerly in William's group) and Eban Brown (falsetto).
