Ah, these are among my fondest memories of early, early childhood! Lancelot Link: Secret Chimp was created by former Get Smart writers: the show is essentially a riff on the get Smart idea, with an all-chimpanzee cast. Lancelot Link is a spy who works for the Agency to Prevent Evil (Ape). His love interest is Mata Hairi; the villain is Baron von Butcher. Bursting into psychedelic song periodically is the all-chimp rock band the Evolution Revolution:
I am amused to read that the writers wrote the scripts backwards; they’d get the chimps onto the soundstage, and then improvise the dialogue to match the ape’s lip movements. Hence the many truly absurd moments on the show, when for no apparent reason the characters would break into song or go into some non sequitur. One of the voice over actors was Bernie Kopel who had played Siegfried on Get Smart. The show (whcih was expensive to produce, only ran a little over three months, from Sept 1970 through Jan 1971, but they played the reruns liberally.
By the way, Lancelot Link is far from the first chimp-centric entertainment to be loved by American audiences. For some background on that, go here.
To find out more about show business past and present, consult No Applause, Just Throw Money: The Book That Made Vaudeville Famous, available at Amazon, Barnes and Noble, and wherever nutty books are sold.
For more on silent and slapstick comedy please see my new book Chain of Fools: Silent Comedy and Its Legacies from Nickelodeons to Youtube, just released by Bear Manor Media, also available from amazon.com etc etc etc