Willie Piper, an assistant recordist at a music company recording and producing gramophone records, has a loving fiancée, Mary - but that is very much where his luck runs out.

Easily startled, accident prone, underpaid and despised by Mary's pub landlady mother, Willie has saved just about enough to buy a new-build house, but neither a car nor the furniture to go inside it! Without a very small raise - just five shillings - it doesn't seem the couple's situation is going to improve any time soon, and neither wish to raise the ire of Mary's disapproving mother by even announcing their intention to wed before their financial situation improves!

At the factory, meanwhile, the bosses are on the search for a big new hit and, at great expense, have hired a demanding crooner to record the song they've pinned their hopes on, Leaning On A Lamp Post. After a dozen or so takes, at great length in the studio and with a pile of destroyed master recordings behind them, they finally produce a version that both the singer and his even more demanding manager-wife approve of.

And that's when Willie's clumsy, poor-luck strikes.

When a sudden noise startles him, Piper drops and smashes the fresh wax master into pieces, rendering it useless. Unable to orchestrate a re-recording, Mary helps the panicked Willie, a keen banjo player, to record his own version of the song - and when it is duly published, becomes a huge hit overnight!

This could be the financial and occupational salvation Willie and Mary have been seeking all along, but first there's a police case, an irate crooner, a truckload of stolen furniture, and even his own identity to contend with!