David Bruce Cassidy (born April 12, 1950) is an American actor, singer and guitarist. Cassidy is perhaps best known for his role as Shirley Jones's oldest son, Keith Partridge, on the popular 1970s musical/situation comedy, The Partridge Family from 1970 to 1974. He subsequently went on to a successful pop career in the mid to late 70s, and still performs on stage on a regular basis. Biography Early life Cassidy was born at Flower and Fifth Avenue Hospital in New York, New York, the son of Irish American actor Jack Cassidy and actress Evelyn Ward. Career In his early career Cassidy was featured on Bonanza, Adam-12 and Ironside. In 1970 he took on the part of Keith Partridge, son of Shirley Partridge, who was played by Cassidy's real-life stepmother Shirley Jones. When he was first hired to play Keith on The Partridge Family, he was not slated to actually