This video collage that I made is from the game show, "Password" that aired on ABC from April 5, 1971 to June 27, 1975.
The host was Allen Ludden.
Supposedly, the theme song is called "The Fun Of It" by Score Productions.
The ABC version is considered to be almost completely gone. GSN aired the complete Brett Somers/Jack Klugman episode on the morning of September 11, 2006. Klugman also appeared on the ABC version of Password with Tony Randall in an episode of The Odd Couple. A second studio master, from 1972 and featuring Sheila MacRae and Martin Milner, is also known to have survived. Three more episodes survive on the videotape trading circuit, as recorded by home viewers: the Password All-Stars finale; a 1975 episode with Betty White and Vicki Lawrence; and the 1975 finale with Kate Jackson and Sam Melville. A few more episodes from the ABC version also exist at UCLA's film and television archive. It is believed that the videotapes that were used for the ABC version of Password were recycled and reused for the Richard Dawson version of Family Feud and The Better Sex (which later got erased) a few years later.