This 1944 musical comedy stars Gene Kelly and Rita Hayworth. (We got on kind of a Rita Hayworth kick after watching Gilda.) It invites comparison with Singin' in the Rain. And that comparison is: "It's nowhere near as good as Singin' in the Rain." But let me explain:
Mr. Kelly plays Danny, proprietor of a semi-seedy Brooklyn nightspot, featuring vaudeville-style skits and production numbers. Ms. Hayworth is Rusty, one of the chorus girls, and also Danny's sweetheart. Phil Silvers is also in the mix as "Genius", a comic who might have seemed funny in the 1940s.
So Rusty (and the rest of the chorus) notice a ad for a Vanity magazine cover girl. After a series of merry mixups, and the coincidental fling of the magazine's owner with Rusty's grandmother back in the day, she lands the job. And (since she looks just like frickin' Rita Hayworth) she finds herself on the path to glamorous stardom. And wooed by a rich playboy.
Leaving Danny behind? Don't worry, this is a comedy, not A Star is Born.
The script is straight out of Cliché Central. The songs are forgettable. Acting is OK.
But Gene Kelly saves the day when he starts dancing. As usual. And (just like Singin' in the Rain) he makes his dance partners look good too. No spoilers, but there's a number where cinematic trickery is used to give him a very unexpected partner; I'm surprised the technology of 1944 was up to that.