It is not necessary to have seen the movie Monty Python and the Holy Grail to enjoy the Mercury Theater's buoyant 
new production of the musical Spamalot, though it might help you understand the scene in which King Arthur reduces the persistent-but-stupid Black Knight piece by piece.
For those who love the 1975 movie satire of the glamorized Arthurian legend—I was a passionate late-teen fan of Monty Python at the time—Spamalot has the best of the classic bits. Arthur and the Knights of the Round Table pretending to ride horses while their squires bang coconut shells together to imitate the sound of hooves. That Black Knight. The rude Frenchman firing outrageous taunts to Arthur and the Knights from a castle turret (including the classic line, "I fart in your general direction"). The shrubbery-demanding Knights Who Say Ni. Prince Herbert, who rejects an arranged marriage to the daughter of a wealthy landowner because he wants to... sing! Tim the Enchanter, the killer rabbit and the Holy Hand Grenade.
But Spamalot is not your father's Monty Python. The movie has lots of comic gore, including the murder of a modern historian explaining the Arthurian legend at the hands of a sword-wielding horseman, and Sir Lancelot carving his way through the wedding party to rescue what he thinks is a damsel in distress (but turns out to be Prince Herbert). Spamalot trades bloodletting—even the occasional dismemberment is bloodless—for non-stop jokes and song-and-dance routines by an extraordinarily talented and versatile cast, whose singing voices filled the small (280-seat) Lakeview theater.
While the slender Graham Chapman of the Monty Python troupe played Arthur with an air of baffled world-weariness, Jonah D. Winston—built somewhat like an NFL defensive end — dominates the Spamalot stage cheerfully as a vainglorious King of All Britons. (This role was created in the original Tony-winning Broadway musical in 2005 by Tim Curry.) At the opening of the second act, he joins squire Patsy (Greg Foster) in a rendition of "Always Look on the Bright Side of Life," borrowed from the 1979 Monty Python movie The Life of Brian.
The central role of the Lady of the Lake is the biggest switch in the story line. Played with pizzazz by flaming redhead Meghan Murphy, the Lady of the Lake is a leading character who channels various stage legends through her show-stopping musical numbers. In the movie, the Lady does not appear, and is only mentioned by Arthur, who explains to a communism-spouting peasant that he rules because the Lady in the Lake gave him the sword Excalibur (to which the peasant responds that one does not deserve to be king just because "some watery tart threw a sword at you").
Meghan Murphy as The Lady of the Lake. Credit: Morgan Merceieca/Mercury Theater
That scene is replayed in Spamalot, but the mud-caked peasant, played by David Sajewich, is persuaded to join the Round Table and emerges as the perfectly coiffed Sir Galahad. The cowardly Sir Robin (played here by Adam Ross Brody and in the Broadway original by David Hyde Pierce of TV's Frasier) emerges unscathed as an aspiring actor in Spamalot, whereas in the movie he was cast into the Gorge of Eternal Peril for failing to answer a trick question at the Bridge of Death.
Meanwhile, Lancelot (Karl Hamilton) realizes something about himself after rescuing Prince Herbert that might not have been well-accepted in a movie (gasp!) 45 years ago, but went over very well in 2019 in a room filled with an opening-night audience a few blocks west of Boystown. This culminates is a wildly colorful dance number straight out of Peter Allen.
Sir Lancelot's coming-out party in Spamalot. Credit: Morgan Mercieca/Mercury Theater
The theater book elides the subplot from the movie in which modern British police investigate the murder of the historian and in the final scene interrupt a climactic massed charge at the rude Frenchman's castle by driving up and arresting Arthur and his surviving party. But there is plenty of anachronism, including references to Broadway, the important role of Jews in the theater industry, Fiddler on the Roof, Yentl, West Side Story and more. And there is some nice localization (look for the Cubs' "W" flag and a reference to Antioch, Illinois).
This production is highly recommended, and if you don't walk out grinning, that Frenchman might blow his nose at you. Spamalot has been extended thru December 29. Tickets are $40-$70 for shows at 8pm Wednesdays-Saturdays, with 3pm matinees on Saturdays and Sundays. The Mercury Theater is located at 3745 N. Southport Ave., two doors up from the Music Box movie house.