The departure of founder Al Kooper and trumpet player Randy Brecker following the release of Blood Sweat & Tears' debut album in early 1968 didn't bode well for the band. But somehow the self-titled follow-up, released in December 1968, became their breakthrough moment.

Credit a move toward mainstream pop music, as producer James William Guercio (who'd soon become known for his work with Chicago, with whom he was simultaneously producing) and a reformulated lineup (now including gruff-voiced singer David Clayton-Thomas) helped the band spin off three consecutive Top 5 singles in "You've Made Me So Very Happy," "And When I Die" and "Spinning Wheel." It helped that they enlisted outside songwriters for the project; Motown's Berry Gordy co-wrote "Happy," while Rock and Roll Hall of Famer Laura Nyro penned "And When I Die."

Blood, Sweat & Tears hurtled to the top of the album chart, but that sudden success brought consequences. "When I joined BS&T, there was already a lot of political infighting," Clayton-Thomas told Maclean's a few years ago. "And by 1969 we had the No. 1 album in the world. Throw $20 million into the mix, and love beads and flower power go out the window. There were nine guys in the band, and each one had a girlfriend or family telling him, 'You're the real star, you don’t need those other guys.'"

By January 1972, Clayton-Thomas was gone. But he left quite a legacy on that album. Still, its success wasn't guaranteed. After all, the group's first album, Child Is Father to the Man, wasn't a hit. And Blood, Sweat & Tears was playing around with jazz-inflected rock before it was a proven commodity.

The opening track, for instance, is adapted from 19th-century avant-garde composer Erik Satie's "Trois Gymnopedies," while "Blues: Part II" incorporates elements of Cream's "Sunshine of Your Love." Elsewhere, BS&T take on both Traffic ("Smiling Phases") and Billie Holiday ("God Bless the Child") to create an endlessly intriguing mix of radio-ready moments and offbeat exploration, which ultimately earned the group a staggering 10 Grammy nominations, including best song for "Spinning Wheel."

On their self-titled second album, Blood Sweat & Tears had pioneered a new sub-genre of pop music, something you might call Big Apple Rock. Clayton-Thomas once described this amalgam as "bass and jazz -- Broadway brass horns. It’s New York City music. You can hear the taxi cabs and the horns and the clanging of the streetcars and everything in the music. It ain’t country music, OK? It’s big-city music."

Top 100 Albums of the '60s