He produced Perry Como's first hit records and signed Glenn Miller to his final contract.
In the late 1950s he became administrative assistant to the president of Warner Bros. Records and was instrumental in launching Bob Newhart and The Everly Brothers.
At Capitol Records in the 1960s, as vice president and general manager of Beechwood Music, Hendler signed up some 200 songwriters across the country and had more than a dozen top 40 hits.
Featuring Kay Cole (creator of the role of Maggie in A Chorus Line), Ted Neeley and Richard Hatch, it was presented in Los Angeles in 1968 and optioned for Broadway by his co-producer Hal James, producer of Man of La Mancha.
Hendler wrote the book and lyrics for Rock Carmen, which he co-produced and directed at the Roundhouse, London, in 1972,[9][10][11] featuring Elaine Paige.