Scooby-Doo
The first episode of "Scooby-Doo, Where Are You!" "What a Night for a Knight" debuted on the CBS network Saturday, September 13, 1969. The original voice cast featured veteran voice actor Don Messick as Scooby-Doo, radio DJ Casey Kasem (later host of radio's syndicated "American Top 40") as Shaggy, actor Frank Welker (later a veteran voice actor in his own right) as Fred, actress Nicole Jaffe as Velma, and musician Indira Stefanianna Christopherson as Daphne. Scooby's speech patterns closely resembled an earlier cartoon dog, Astro from "The Jetsons" (1962–63), also voiced by Messick. Seventeen episodes of "Scooby-Doo Where are You!" were produced in 1969–70. The series theme song was written by David Mook and Ben Raleigh, and performed by Larry Marks.
The Scooby-Doo Show
Despite the yearly changes in the way they were broadcast, the 1976–1978 stretch of "Scooby" episodes represents, at three seasons, the longest-running format of the original show before the addition of Scrappy-Doo. The episodes from all three seasons have been rerun under the title "The Scooby-Doo Show" since 1980; these "Scooby" episodes did not originally air under this title. The credits on these syndicated versions all feature a 1976 copyright date, even though some were originally produced in 1977 and 1978. Outside the United States, reruns aired on CBBC in the United Kingdom until 2015. Like many animated series created by Hanna-Barbera in the 1970s, the show contained a laugh track created by the studio.