In Disney's take on the Alexander Dumas tale, Mickey Mouse, Donald Duck and Goofy want nothing more than to perform brave deeds on behalf of their queen (Minnie Mouse), but they're stymied by the head Musketeer, Pete. Pete secretly wants to get rid of the queen, so he appoints Mickey and his bumbling friends as guardians to Minnie, thinking such a maneuver will ensure his scheme's success. The score features songs based on familiar classical melodies.
Mickey guest-directs a radio orchestra. The sponsor loves the rehearsal, but come the actual performance, Goofy drops all the instruments under an elevator, so they sound like toys. The sponsor hates it, but the audience loves it anyway.
The gang throws Mickey a surprise birthday party; his present is an electric organ, which Minnie plays while Mickey does a jazzy dance. Goofy bakes the cake, but keeps having trouble with it falling. The gang does a conga line to a Latin tune.
Mickey hosts an amateur hour radio show. Among the acts: Donald forgetting the words to "Twinkle Twinkle Little Star"; Clara Cluck singing and chasing the microphone; and Goofy with an elaborate one-man-band contraption.
Mickey and friends put on a revue for the orphans. Donald recites nursery rhymes, but the orphans torment him. Horace, Goofy, and Clarabelle do a dance number. Donald tries again. Clara clucks a song while Mickey plays piano (with support from an unseen orchestra). Donald returns, and the orphans finally send a parade of bricks and eggs on balloons over him and use slingshots to drop them on his head.
It's the 1890's, and Donald is riding his penny-farthing bicycle to see Daisy when Chip 'n Dale make fun of him. It quickly escalates into a full-fledged war between Donald and the chipmunks.
The gang is on vacation. Goofy has some surfing problems, Donald learns why you don't wear a grass skirt near a fire, Pluto and a starfish have a tiff, followed by an encounter with a hermit crab.
Mickey leads his polo team Donald (on a mule), Goofy, The Big Bad Wolf against an all-star team: Stan Laurel, Oliver Hardy, Harpo Marx (on an ostrich), Charles Chaplin, in a game refereed by Jack Holt. Featured spectators include the Three Little Pigs with Shirley Temple, W.C. Fields, and Clarabelle Cow with Clark Gable. Game action proceeds pretty much as you might expect from this bunch of comedians.