Editing Happy Days (section)

=== Theme music ===
{{Main|Happy Days (TV theme)}}
Season one used a newly recorded version of "[[Rock Around the Clock]]" by [[Bill Haley & His Comets]] (recorded in the fall of 1973) as the opening theme song. This recording was not commercially released at the time, although the original 1954 recording returned to the American [[Billboard magazine|Billboard]] charts in 1974 as a result of the song's use on the show. The "Happy Days" recording had its first commercial release in 2005 by the German label Hydra Records. (When ''Happy Days'' entered [[broadcast syndication|syndication]] in 1979, the series was retitled ''Happy Days Again'' and used an edited version of the 1954 recording instead of the 1973 version.) In some prints intended for reruns and overseas broadcasts, as well as on the Season 2 DVD set release and later re-releases of the Season 1 DVD set, the original "Rock Around the Clock" opening theme is replaced by the more standard "Happy Days" theme, because of music rights issues.

The show's closing theme song in seasons one and two was a fragment from "Happy Days" (although in a different recording with a different lyric from that which would become the standard version), whose music was composed by [[Charles Fox (composer)|Charles Fox]] and whose lyric was written by [[Norman Gimbel]]. According to SAG, this version was performed by [[Jim Haas]] on lead vocals, [[The Ron Hicklin Singers]], Stan Farber, Jerry Whitman, and Gary Garrett on backing vocals, and studio musicians.

From seasons three to ten inclusive, a longer version of "Happy Days" replaced "Rock Around the Clock" at the beginning of the show. Released as a single in 1976 by [[Pratt & McClain]], "Happy Days" cracked the Top 5. The show itself finished the 1976–77 television season at No. 1, ending the five-year [[Nielsen ratings|Nielsen]] reign of ''[[All in the Family]]''.

For the show's 11th and final season (1983–84), the theme was rerecorded in a more modern style. It featured Bobby Arvon on lead vocals, with several back-up vocalists. To accompany this new version, new opening credits were filmed, and the flashing ''Happy Days'' logo was reanimated to create an overall "new" feel which incorporated 1980s sensibilities with 1950s nostalgia (although by this time the show was set in 1965).