<P> The revised show was re-pitched to Silverman, who liked the material but, disliking the title Mysteries Five, decided to call the show Who's S-S - Scared? Silverman presented Who's S-S - Scared? to the CBS executives as the centerpiece for the upcoming 1969--70 season's Saturday morning cartoon block . CBS president Frank Stanton felt that the presentation artwork was too scary for young viewers and, thinking the show would be the same, decided to pass on it . </P> <P> Now without a centerpiece for the upcoming season's programming, Silverman had Ruby, Spears, and the Hanna - Barbera staff revise the treatments and presentation materials to tone down the show and better reflect its comedy elements . The rock band element was dropped, and more attention was focused upon Shaggy and Too Much . According to Ruby and Spears, Silverman was inspired by Frank Sinatra's scat "doo - be-doo - be-doo" at the end of his recording of "Strangers in the Night" on a flight to one of the development meetings, and decided to rename the dog "Scooby - Doo" and re-rechristen the show Scooby - Doo, Where Are You! The revised show was re-presented to CBS executives, who approved it for production . </P> <P> Scooby - Doo, Where Are You! made its CBS network debut on Saturday, September 13, 1969 with its first episode, "What a Night for a Knight". 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 . </P> <P> Each of these episodes features Scooby and the four teenage members of Mystery, Inc., Fred, Shaggy, Daphne and Velma, arriving at a location in the "Mystery Machine", a van painted with psychedelic colors and flower power imagery . Encountering a ghost, monster, or other supernatural creature who is terrorizing the local populace, they decide to investigate . The kids split up to look for clues and suspects while being chased at turns by the monster . Eventually, the kids come to realize the ghost and other paranormal activity is actually an elaborate hoax, and--often with the help of a Rube Goldberg - like trap designed by Fred--they capture the villain and unmask him . Revealed as a flesh and blood crook trying to cover up crimes by using the ghost story and costume, the criminal is arrested and taken to jail, often repeating something nearly identical to "...and I would have gotten away with it, too, if it hadn't been for you meddling kids!" </P>

When did the first scooby doo episode air