Written by Python’s Eric Idle, Spamalot is about King Arthur creating the Knights of the Round Table to find the Holy Grail, but it is also about how to make a Broadway musical. Its best song is just like the big number in all Broadway musicals; it’s even called “A Song That Sounds Like This.” But someone says it can’t be a Broadway show because “we don’t have any Jews.” Silly? Yes. And so funny that the show won the Tony as Best Musical in 2005 and has played in at least twenty countries.

Sutter Street Theatre has again done the impossible, presenting this version with a cast of 22 playing at least 30 roles. Genius director Connie Mockenhaupt has made it work, aided by the magnificent accompaniment of John Wilder, the fantastic costumes by Eileen Weaver, and the inventive choreography of Dian Hoel, who has chorus girls and Can Can dancers invading every scene. Sutter Street is at its best when doing musicals, and this show adds another jewel to its crown.

The show opens with a historian, (Mike Jimena) reading a history of medieval England. The cast thought he said “Finland,” and perform a dance slapping each other with fish. When we’re back in England we meet Robin (Michael Sandidge) collecting victims of the plague. Lancelot (Derek Byrne) drags in a corpse (the rubber-faced Tom Bost) who sings and dances to prove he’s “Not Dead Yet.”

King Arthur, played by Rick Kleber, whose rich baritone will be remembered from last season’s “Guys and Dolls,” appears accompanied by his servant Patsy (Mark Androvich), who claps two coconut shells to sound like the hooves of his horse. Arthur is recruiting knights for his quest, and Robin and Lancelot agree to join him. He soon confronts a very left-wing peasant, Dennis Galahad (the hilarious Scott Minor) who attacks Arthur for not being properly elected. Arthur bases his claim to be ruler on the evidence of the sword Excalibur, and conjures the Lady of the Lake (Allison Gilbreath) who gave him the sword. She and her “Laker Girls” turn Dennis into Sir Galahad. God (a voiceover) sends Arthur and his knights off on their holy quest.

Act Two continues along the same silly lines including a meeting with the terrifying Knights who say Ni, who demand that Arthur produce a shrubbery. The Lady of the Lake reappears, complaining that she hasn’t been seen in this act, singing “Whatever Happened to My Part?”

There are too many more subplots to describe here, and sight gags pop up in every corner. If you think that silly can be terrific fun, you must see this show, which I predict will be selling out every performance. The show ends as “a show that ends like this,” a wedding, and an audience sing along with the cast.