Born in Palestine, Mekler was a classically trained pianist. Upon arriving in Los Angeles, California, Mekler sought out Dunhill Records and was hired as a staff producer, despite his lack of production experience or familiarity with rock and roll and pop music. His first project at Dunhill was with folk-pop band The Lamp of Childhood, where he oversaw studio sessions, contributed songs and played piano. The group's three singles flopped but Mekler's next project, Steppenwolf, made music history.[2] It was Mekler who suggested the name "Steppenwolf" to the band's members, having just read the Hermann Hesse novel.[3] As the producer on Steppenwolf, the 1968 debut by that group, Mekler helped craft the sonic onslaught that would unleash the term "heavy metal" upon the world, a line from the brother of drummer, Jerry Edmonton, in the song, "Born to Be Wild".

The mysterious Mars Bonfire was Dennis Edmonton, lead guitarist for Jack London & The Sparrows. The Oshawa, Ontario group was the beginnings of Steppenwolf and producer Mekler's contributions on psychedelic tracks such as "Born to Be Wild" and "Magic Carpet Ride". A year after the Steppenwolf recordings, Mekler launched hits from Three Dog Night such as "One", "Try a Little Tenderness", "Eli's Coming", "Easy to Be Hard" and "Celebrate". Other studio credits include keyboard work with Cher, Donovan and David Clayton-Thomas as well as producing songs for Dinah Washington.[4]

In 1971, Mekler founded his own labels, Vulture and Lizard Records, based on Sunset Boulevard in Los Angeles. Artists signed to Lizard/Vulture included Nolan Porter, Clydie King, Paul Humphrey & the Cool Aid Chemists and The Frantics. Despite national chart success both Vulture and Lizard Records collapsed in mid 1972.[5] Mekler remained in demand for his production talent until his death, from a motorcycle accident, in September 1977.[6]

Mekler also produced Genya Ravan's Goldie Zelkowitz album, the title utilizing her stage name from Goldie and the Gingerbreads, and her father's last name, who died during this recording.