Within a year of his screen test, he had been signed to his life-changing role as the oldest child in a family of five aspiring pop singers and their musically gifted mother — played by Shirley Jones, Cassidy's real-life stepmother. By the time he was 20, Cassidy was one of the world's most recognizable television and music stars, even though he had never sung publicly until he became Keith Partridge.
(The original idea was that all of the child actors would lip-sync the Partridge Family's musical numbers; shortly after the show went into production, the dusky-voiced Cassidy convinced the show's producers that he could hold his own vocally alongside Jones, who had already starred in film versions of musicals, including Oklahoma, Carousel and The Music Man.)
Within two months of the debut of The Partridge Family on ABC in September 1970, Cassidy had a No. 1 hit on the Billboard Hot 100 chart — "I Think I Love You" — billed as "The Partridge Family Starring Shirley Jones Featuring David Cassidy."
During an era when the Big Three broadcast networks still had a monolithic hold on pop culture, Cassidy's picture was suddenly everywhere — not just on the fronts of magazines and record albums, but on lunch boxes, posters, cereal boxes and toys. He sold out concert venues across the globe, from New York's Madison Square Garden to stadiums in London and Melbourne.
By 1972, Cassidy already was aching to shed his bubble-gum persona. Like legions of teenage stars before and after him, he played up his sex appeal to underscore his adulthood; in a cover story for Rolling Stone — with a portrait shot by Annie Leibowitz cropped just below the top of his pubic hair — he talked about his drug use: "Not smack," he explained, "but grass and speed and psychedelics."
The Partridge Family was cancelled in 1974; Cassidy had some success as a solo musical act after that, but he felt as if he couldn't escape being Keith Partridge.
"They're merchandising your name and your face and your likeness," he told NPR in 1981. "And I felt kind of robbed of my identity."
Cassidy left acting for about three years while he tried to figure out what to do next. By the 1980s, he had started to appear in musical theater, both on Broadway and in London's West End.
But in his personal life, he eventually seemed to spin out entirely. In the 2010s, he had a string of arrests on drunk-driving charges in Florida, New York and California. In 2014 he told CNN, "I am most definitely an alcoholic." The following year, he declared bankruptcy and was charged with a hit-and-run in Fort Lauderdale.
David Cassidy is survived by two children, Beau and Katie Cassidy; his ex-wife, Sue Shifrin-Cassidy; his half-brothers Shaun, Patrick and Ryan Cassidy; his stepmother, Shirley Jones; and several nieces and nephews.
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