Radio comedy, or comedic radio programming, is a radio broadcast that may involve variety show, sitcom elements, sketches, and various types of comedy found in other media. It may also include more surreal or fantastic elements, as these can be conveyed on a small budget with just a few sound effects or some simple dialogue. Radio comedy began in the United States in 1930, based on the fact that as most United Kingdom music hall comedians such as Charlie Chaplin and Stan Laurel progressed to silent films, they moved to Hollywood and fed the radio comedy field. Another British music hall comic, George Formby, stayed in the British movie industry, and in 1940 joined the Entertainments National Service Association to entertain British World War II troops. UK radio comedy therefore started later, in the 1950s. Radio comedy began in the United States in 1930, and got a much later start in the United Kingdom because many of the British comedians (such as Charlie Chaplin and Stan Laurel) emigrated to the U.S. to make silent movies in Hollywood, and the American comedians who did not become dramatic actors migrated to radio. Raymond Knight launched The Cuckoo Hour on NBC in 1930, along with the 1931 network debut of Stoopnagle and Budd on CBS. Comedians such as Fred Allen, Jack Benny, Judy Canova, Bob Hope and Red Skelton were top-rated in the decades that followed. Even after the big name comedians moved to television in the 1950s, radio comedy continued, notably from Bob and Ray (1946–1988), The Firesign Theatre (1966–1972), and segments heard on NBC's Monitor (1955–1975). Radio comedy did not begin in the United Kingdom until a generation later, with such popular 1950s shows as The Goon Show (started 1951) and Hancock's Half Hour (started 1957). Later, radio became a proving-ground for many later United Kingdom comedians. Chris Morris began his career in 1986 at Radio Cambridgeshire, and Ricky Gervais began his comedy career in 1997 at London radio station XFM.