Jazz-rockers Blood, Sweat & Tears, led by core member and singer David Clayton-Thomas, performs March 12-13 at John Ascuaga’s Nugget.

Clayton-Thomas is the voice behind the band’s biggest hits, including “Spinning Wheel,” “You’ve Made Me So Very Happy,” “And When I Die” and “More and More.” He’s also been with the band nearly every year since the band’s 1969 hit album, “Blood, Sweat & Tears.”

Blood, Sweat & Tears was founded in 1967 by Al Kooper, who led the band through its first release, “Child is Father to the Man,” in 1968. Kooper left the band shortly after, and he was replaced by the gravel-voiced Clayton-Thomas, who led the group to platinum-selling status with its second and self-titled album in 1969.

Though Kooper was credited with arranging some of the material for the album before his departure, it was Clayton-Thomas’s voice that produced the hits.

The musical and personal journey for Clayton-Thomas was a long and tumultuous road. In the spring of 1962, at age 21, Clayton-Thomas walked out of Millbrook Reformatory with $20 to his name and a battered old guitar.

Since age 15, he had been jailed several times for vagrancy, parole violations and petty theft. The Toronto native credits that old guitar as his saving grace; it had been left behind by another inmate.

His first venture into the recording studio produced “Boom Boom,” a John Lee Hooker blues song that quickly became a local hit. He then wrote “Walk that Walk” and “Brainwashed,” both of which were No. 1 hits in Canada. His success continued with Blood, Sweat & Tears.

The band’s horn section gave this rock band a soul-drenched jazz sound, and the second album yielded a career’s worth of hits in just six months. It sold 3 million copies and won the Grammy for Album of the Year.

By 1972, the band had a greatest-hits album out, which pulled together four albums the band did in just four years. The second album remains the band’s biggest seller ever, after the band went on to produce scores of other albums.

An interesting blip in the group’s career came in 1970, when the band was pressured by the United States State Department to do a tour of Eastern Europe to bolster support for the war in Vietnam.

Reports said even the band was unaware of the motives for the tour, but the band did it to ease pressure on Canadian Clayton-Thomas’s visa status. In the end, it made a lot of potential fans turn away from the band.

Blood, Sweat & Tears became one of the first rock acts to play in Las Vegas in the early 1970s. Though the band was criticized for playing the then rock-unfriendly town, it was a move that helped open the doors of Las Vegas to the rock world.

In the years to follow, the band went through numerous lineup changes, and Clayton-Thomas left the group following “BS&T 4.” After three albums without him, the band welcomed Clayton-Thomas back.

Blood, Sweat & Tears continued to make new albums over the years. “Blood, Sweat & Tears’ Greatest Hits (Remastered)” was released by Sony in 1999. The 13-track effort features most of the band’s best-known tracks.