Sid Mark is an American radio disc jockey based in Philadelphia, Pennsylvania, who hosts weekly radio programs featuring the music of Frank Sinatra. His Philadelphia-area shows include Friday with Frank, airing Friday evenings, Sunday with Sinatra, airing Sunday mornings, and The Sounds of Sinatra, syndicated nationally.[1] The first iteration, Friday with Frank, began airing in 1957 over WHAT-FM, where Mark was a disc jockey, and has been running continuously ever since.