The core of the O'Jays – Eddie LeVert, Walter Williams, and William Powell – had been together for 14 years when they had their first big hit, "Back Stabbers," during the summer of 1972. Their career had gyrated everywhere except up when they joined forces – for a second time – with Kenny Gamble and Leon Huff shortly after the songwriting-production team formed their label Philadelphia International.

The group had done plenty of excellent work over the years – "One Night Affair" and "Let Me in Your World," from 1969's The O'Jays in Philadelphia (Epic/Legacy), for example – but "Back Stabbers" was in a class by itself. The ode to ugly, everyday paranoia kick-started an album of the same name that produced four more hit singles, including "992 Arguments," "Time to Get Down," "Sunshine," and the fabulous "Love Train." "Back Stabbers" and "Love Train" – thematic bookends to the terrain Gamble and Huff carved out for the group – were cuts that made a person stand up and take notice. At a time when funk was beginning to take charge of black music, the O'Jays were cranking out powerful, driving gospel-tinged soul built around LeVert's passionate, steamrolling baritone and Williams's tenor and beautiful falsetto. Beginning with "Back Stabbers," they went on a run that that lasted through 1978 and made them arguably the best soul vocal group of the day.

The time was right for all concerned. They had the vision and skill that came with years of experience – and a state-of-the-art studio. But if their talents were strictly present tense, the collaboration was marked by value that even then was hard to find: the music was what mattered, and it took everyone's contribution to create what they were after. The studio band ranked with any found at Stax and Hi Records, the O'Jays had a pair of lead voices, and harmonies were layered so thick that a chorus typically sounded like the choir and the congregation. In that sense, their appeal was old-fashioned – as the more recent collaboration between LeVert and his son Gerald acknowledges – and like many others, the O'Jays went out of fashion when disco arrived and never made it back.

If you don't know what you missed, buy Essential O'Jays and find out. It's as strong a collection of soul music as you'll find anywhere. (J.H. Tompkins)