David Cassidy, the teen and pre-teen idol who starred in the 1970s sitcom "The Partridge Family" and sold millions of records as the musical group's lead singer, has died after being diagnosed with dementia earlier this year." The Partridge Family" aired from 1970-74 and was a fictional variation of the '60s performers the Cowsills, intended at first as a vehicle for Shirley Jones, the Oscar-winning actress and Cassidy's stepmother. The cast also featured Cassidy as eldest son. Cassidy's appeal faded after the show went off the air, although he continued to tour, record and act over the next 40 years, his albums including "Romance" and the awkwardly titled "Didn't You Used To Be?" He was 67.