As the show shifted to a live studio audience and focused more on Henry Winkler's Fonzie character, producers replaced the opening with the now-iconic "Happy Days" theme.
A final, more "contemporary" version of the theme was introduced for the show's farewell season. The Songwriters and Singers happy_days_theme_song
The opening theme was "Rock Around the Clock" by Bill Haley & His Comets. This choice was inspired by the song's successful use in the 1973 film American Graffiti , which also starred Ron Howard. As the show shifted to a live studio