Penny Marshall
Garry Marshall, creator and then part-time writer for "Happy Days", cast Marshall and Cindy Williams to guest on an episode of the show. The installment, titled "A Date with Fonzie", aired on November 11, 1975 and introduced the characters Laverne DeFazio and Shirley Feeney (played by Marshall and Williams, respectively). In that episode, Laverne and Shirley were a pair of wisecracking brewery workers who were dates for Fonzie (Henry Winkler) and Richie (Ron Howard). The pair were such a hit with the studio audience that Garry Marshall decided to co-create and star them in a successful spinoff, "Laverne & Shirley" (1976–1983). The characters of Laverne and Shirley appeared in five more episodes of "Happy Days". In 1982 at the beginning of "Laverne & Shirley"s eighth season, Williams left the show due to her pregnancy. Marshall continued with the show, but it was canceled after the season's final episode aired in May 1983.
Happy Days
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 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 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, the original "Rock Around the Clock" opening theme is replaced by the more standard "Happy Days" theme.