It is a musical based on the songs of that legend of Tin Pan Alley, Irving Berlin. A violinist named Roger (Power) has ambitions to make it as a bandleader in the emerging genre of swing music. His band, which includes his best friend Charlie (Ameche), finally gets a chance to play in a San Francisco dive bar. There they meet singer Stella Kirby (Faye), and via a heavy dose of Meet Cute she becomes the singer in their band. They climb the ladder of success, graduating from dive bars to respectable theaters, and Roger (now called "Alec" after the song "Alexander's Ragtime Band") and Stella fall in love. However, after Stella gets an offer to star on the New York stage, she and Roger/Alec break apart.
Originally supposed to be a Biopic of Irving Berlin, but became a fictional story after Berlin balked. Ethel Merman plays Jerry, Stella's replacement as singer for the band. John Carradine has a small part as a cab driver. Alfred Newman arranged the Irving Berlin soundtrack for the screen.
- Belligerent Sexual Tension: Lots of yelling between Stella and Alec in the early going, after she gets involuntarily drafted into their band. After they kiss, Alec says "And that's for all the times I wanted to wring your neck."
- Book-Ends: "Alexander's Ragtime Band" as the first musical number and the last.
- Buxom Is Better: The Belligerent Sexual Tension is cracking by the time when Alec notes Stella's curvy body while criticizing the frills on her dress.Alec: That might be all right for some skinny little girl, but not a girl with a gorgeous figure like yours.
- Call-Back: Early in the film, Roger's aunt disowns him, and his music coach is appalled, after they find out that Roger is leaving his concert violinist career behind for swing music. The end has his aunt and uncle popping up at his big concert, enjoying themselves immensely.
- Contrast Montage: After Stella finds out that she has lost Alec to Jerry, she quits Broadway. This is followed by a Contrast Montage in which Jerry is singing loud, up-tempo show tunes on big stages, while Stella is singing melancholy love songs in nightclubs and bars.
- Drowning My Sorrows: Alec has to drink for a while after he finds out that Stella and Charlie got married while he was fighting in France.
- In Case You Forgot Who Wrote It: The opening title card actually says "Irving Berlin's 'Alexander's Ragtime Band'".
- I Want My Beloved to Be Happy:
- After they see Alec again and Charlie figures out that Stella still loves Alec, he agrees to give Stella a divorce, just like that.
- Later Jerry does basically the same, telling Alec that she won't marry him because he really loves Stella.
- Jukebox Musical: Actually a mixture of pre-existing Berlin hits like "Alexander's Ragtime Band" and "Easter Parade", and original music written for the film, like "Now It Can Be Told".
- Last-Second Word Swap: After Charlie calls their little group "the three musketeers", an extremely irritated Stella says "the three musketeers, my—my foot."
- Love Triangle: Stella, Alec, and Charlie, with Charlie swooping in to pick up the pieces after Stella and Alec break up.
- Meet Cute: Stella and Roger meet at the bar when he accidentally steals the song she was going to sing (see They Stole Our Act below).
- Proscenium Reveal: What appears to be Davey waking up at reveille at boot camp, is revealed to be the "Oh, How I Hate to Wake up in the Morning" number that Alec's army unit is staging.
- Secret Test of Character: Charlie reveals to Alec that he and Stella have gotten divorced. When he follows that remark by harshly condemning Stella as a "double crossing two-timer", Alec angrily defends Stella's honor. Charlie smiles, says "that's all I wanted to hear," and agrees to help Alec find Stella.
- They Stole Our Act: Stella comes into the bar and leaves her sheet music for "Alexander's Ragtime Band" on the table. After Roger realizes they forgot the sheet music for their song, he panics and snatches Stella's music off the bar counter. Stella gets pissed when she hears it, jumps on stage uninvited, starts singing, and presto, she's part of the band.
- Time Passes Montage: World War I is covered with some Stock Footage of combat and of troops returning home.
- Titled After the Song:
- After Berlin's 1911 hit "Alexander's Ragtime Band".
- And in universe Roger, who's called "Alec" continually after he and his band hit it big.
- Tomboyish Name: Ethel Merman's character is called "Jerry", a name that rather fits her brassy personality.