But it was his iconic role as Keith Partridge, son of Shirley Partridge (stepmother Jones) that rocketed Cassidy to stardom when the show hit screens in 1970. The show centered around a singing family act from California -- based on cult family band The Cowsills -- who, with the aid of their irascible manager, Reuben Kincaid, score a top 40 hit and then go on the road in their signature colorful school bus to play shows and engage in various wacky adventures. With Cassidy as its lead singer, the fake band scored a real hit with their debut bubblegum confection "I Think I Love You," which hit No. 1 on the Billboard Hot 100 in November 1970.
Like many teen idols who eventually grow weary of the screaming and crushing adulation of their breathless fans (aka "Cassidymania"), Cassidy grew tired of his Tiger Beat fame and began to rebel against his Partridge family character's squeaky clean image, which appeared on hundreds of licensed items, from lunch boxes and posters to cereal boxes comic books and toys. His break from that fresh-scrubbed image began with a nearly-nude Annie Leibowitz-shot Rolling Stone cover in 1972 in which the writer notes that the singer is being shuttled around his hometown high and drunk. To put it in perspective, according to his official bio, during his run on the show, membership in Cassidy's official fan club exceeded that of Elvis Presley and The Beatles. In 1972, Cassidy also released his cover of "Cherish," the 1966 hit by The Association, from his debut album of the same name on Bell Records.
The singer went on to release 10 Partridge albums and five solo efforts while touring to sold-out crowds through the mid-1970s. Feeling besieged by the attention of his female admirers, Cassidy quit the show -- which ended its run in 1974 after 96 episodes -- and focused on recording a string of well-received albums for RCA Records, including 1975's The Higher They Climb and 1976's Home is Where the Heart Is, landing a hit in 1975 with "I Write the Songs," a track that would go on to become Barry Manilow's signature track.
By the end of the decade, though, his musical career waned along with his musical output, aside from a brief blip in 1985 when the George Michael-assisted single "The Last Kiss" gave Cassidy a top 40 hit in Europe. His final album was 1998's Old Trick New Dog on Slamajama Records, which featured a number of Partridge remakes. After hanging up on music, Cassidy starred in the short-lived 1978 police drama David Cassidy: Man Undercover, which bombed, but was essentially the blueprint for the later hit show 21 Jump Street.
The singer turned to theater in the 1980s, touring with a variety of musical productions and in the late 1990s and early 2000s he joined the Las Vegas shows EFX and At the Copa. The thrice-married star continued touring until announcing his retirement in February, at which time he revealed he was suffering from non-Alzheimer's dementia.
Through ups and downs, including well-documented struggles with alcohol and a series of DUI arrests in the 2000s, Cassidy maintained the kind of sunny demeanor that had endeared him to a generation of fans. “I’m an optimist. I mean, you have to be with my career,” he said in his official bio. “I’ve never gone out and changed my style to suit the times. I have always stayed true to myself by using the work ethic my father instilled in me, to strive for the best musically, theatrically, as well as in producing and writing. He taught me to be fearless about revealing the frailties and strengths of the human experience. Bringing that human element to my work is the most important thing I can do as an entertainer.”