Can anyone remember a book 'the little captain'?

[PoppieD]

Am not sure if I've imagined this but for some reason I have this weird scene from a book in my head.. It's kids dancing on a beach in some performance and singing something about Popinjay polly, then melting the money down to make a propellor for a boat? Think it's prob an older book, I grew up late 80s/90s and was def from before this time.

Yes, I have it. I got it in a charity shop last year for ds. it's by Paul Biegel, translated from Dutch, if I remember correctly. Published around early 70s as a rough guess from the cover.