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/Dynomutt Hour
The Scooby-Doo/Dynomutt Hour is a 60-minute package show produced by Hanna-Barbera Productions in 1976 for ABC Saturday mornings. It marked the first new installments of the cowardly canine since 1973, and contained the following segments:"The Scooby-Doo/Dynomutt Hour" debuted on September 11, 1976. After two months, an additional 30 minutes were added to the hour-long series (to accommodate repeats of the first two CBS seasons of "Scooby-Doo, Where Are You!"), becoming the 90-minute "Scooby-Doo/Dynomutt Show," which is how it remained from December 4, 1976 to September 3, 1977.
Like many animated series created by Hanna-Barbera in the 1970s, the show contained a laugh track created by the studio.