Like so many of his contemporaries, Clay's intense vocal style reflects a gospel background. He made the secular jump in 1965, signing with Chicago's One-derful Records and issuing a series of gospel-tinged soul records that were a lot grittier than the customary Windy City soul sound. Clay inaugurated Atlantic's Cotillion subsidiary in 1968 with a supercharged cover of the Sir Douglas Quintet's "She's About a Mover," produced by Rick Hall in Muscle Shoals shortly before the singer joined forces with Hi Records boss Willie Mitchell. With the relentlessly driving Hi Rhythm Section in tow, Clay waxed his biggest seller in 1972, "Trying to Live My Life Without You," later covered very successfully by Bob Seger.

Although Clay's tenure on Hi may have been his most commercially potent, he steadily recorded and gigged ever since. He is a genuine hero in Japan, where he's recorded two sizzling live albums filled with the churning grooves, punchy horns, and searing vocals that inevitably characterize the best deep soul -- no matter where it's recorded, a fact proved by another live set recorded in Switzerland in 2003, Respect Yourself, and released in 2005 by Blind Pig Records. In 2007, Clay returned to the studio and recorded the gospel album Walk a Mile in My Shoes on his Chicago-based Echo label.