Fabulous film quartets include musketeers, Beatles, 'City' girls

The title is a misnomer. The three musketeers - Athos, Porthos, and Aramis - are incomplete without their comrade D’Artagnan. Director Richard Lester acknowledged as much when he followed up his 1973 “The Three Musketeers’’ with a sequel the next year, “The Four Musketeers.’’

So four is the magic number for musketeers. What about the movies, in general? There are enough examples to make you wonder.

D’Artagnan, Athos,

Porthos, and Aramis

Back to back to back to back, these swordsmen are unbeatable. That’s regardless of who’s played them, whether Logan Lerman, Matthew Macfadyen, Ray Stevenson, and Luke Evans, in the new version; Gene Kelly, Van Heflin, Gig Young, and Robert Coote, in 1948; or Don Ameche and the Ritz brothers(!), in 1939. Sometimes the movie they show up in isn’t even “The Three Musketeers.’’ Gabriel Byrne is D’Artagnan, John Malkovich Athos, Gerard Depardieu Porthos, and Jeremy Irons Aramis in “The Man in the Iron Mask’’ (1998). Regardless of who or where, the number remains the same - and irresistible.

THE MARX BROTHERS

All right, Zeppo was just along for the ride. But what a ride it was. And note that the Marxes’ decline began after Zeppo left the act. His being such a dud somehow makes his brothers’ anarchy seem all the zanier by comparison. “Duck Soup,’’ say, or “Horse Feathers’’ just wouldn’t be “Duck Soup’’ or “Horse Feathers’’ without Zeppo.

THE FANTASTIC FOUR

Mr. Fantastic, the Invisible Woman, the Human Torch, and the Thing are the lamest Marvel superheroes to make it to the screen, no question. “Fantastic Four’’ (2005) and “Fantastic Four: Rise of the Silver Surfer’’ aren’t exactly the “Citizen Kane’’ of superhero movies. But think of how much worse each would be if not multiplied by four.

THE BEATLES

The Fab Four is no less fab in “A Hard Day’s Night’’ (1964) and “Help!’’ (1965) (“Yellow Submarine’’ and “Let It Be’’ we won’t talk about.) The endlessly engaging equilateral comprising John, Paul, George, and Ringo is, if anything, even more beautifully balanced on screen than on stage or vinyl.

SPINAL TAP

Not that the Beatles are the only musical quartet to flourish onscreen. David St. Hubbins (Michael McKean), Nigel Tufnel (Christopher Guest), Derek Smalls (Harry Shearer) and various serial exploding drummers make “This Is Spinal Tap’’ (1984) one more example of the entertainment indivisibility of four.

THE FABULOUS CORLEONE BOYS

“Don’t forget, Sonny,’’ Robert Duvall’s Tom Hagen says to James Caan in “The Godfather’’ (1972), “Pop was just as much a father to me as he was to you.’’ Or to Michael (Al Pacino) or Fredo (John Cazale). The Don adopted young Tom when Sonny found him homeless in the streets. Can any four brothers in movie history match them?

THE EARPS

If the Corleones are the greatest quartet of movie brothers on the wrong side of the law, Wyatt, Morgan, Virgil, and James are the greatest to wear badges. From “My Darling Clementine’’ (1946) to “Gunfight at the O.K. Corral’’ (1957) to “Wyatt Earp’’ (1994), there have been at least four good reasons order was kept in Tombstone. (Doc Holliday would make five, except he’s too busy coughing to be counted on.)

DONALD AND HIS NEPHEWS

Without Huey, Dewey, and Louie for support, the world’s most famous duck just wouldn’t be the same. He’d be a lesser version of his great rival Daffy, only with white feathers instead of black, a squawky voice instead of lips, and (terrifying thought) an even worse temper.

THE PROFESSIONALS

Tough hombres don’t come any tougher than Burt Lancaster, Lee Marvin, Robert Ryan, and Woody Strode as they take on the job of rescuing kidnapped Claudia Cardinale in “The Professionals’’ (1966). Or has she been kidnapped? Four heads being better than one, you can count on them to figure things out.

GUNGA DIN AND COMPANY

People think of Rudyard Kipling’s classic adventure “Gunga Din’’ (1939) as being three plus one: The British soldiers (Cary Grant, Victor McLaglen, Douglas Fairbanks Jr.) are over here, and the title character (Sam Jaffe) over there. But they’re all in the same army, right?

NEW YORK’S FINEST

Forget the Los Angeles Rams’ defensive front line in the 1960s. “Sex and the City’’ gal pals Carrie (Sarah Jessica Parker), Samantha (Kim Cattrall), Charlotte (Kristin Davis), and Miranda (Cynthia Nixon), now there’s the real Fearsome Foursome.

THE OZ QUARTET

Think about it. Dorothy is just some kid from Kansas in “The Wizard of Oz’’ (1939). The Scarecrow is nothing more than a guy stuck on a stick. The Tin Woodman needs oiling. The Cowardly Lion is this big pussycat (literally). But put the four of them together, and it’s movie history.

BOB & CAROL & TED & ALICE

“Bob & Carol’’ or “Ted & Alice’’ is a marriage. “Bob & Carol & Ted’’ or “Carol & Ted & Alice’’ is a menage a trois. All four of them together? That’s a hit 1969 comedy and the making of Paul Mazursky’s career.

FRATERNITY OF FOUR

They were adopted, so the Mercer boys (Mark Wahlberg, Tyrese Gibson, Andre Benjamin, Garrett Hedlund) don’t share much of a family resemblance in “Four Brothers’’ (2005). But their eight fists sure pack a mean punch.

Mark Feeney can be reached at mfeeney@globe.com.