Post-war Dutch music

Apologies for the English, my monolingualism is entirely my own fault at this point.

The tldr: my grandmother grew up during WW2 in the occupied Netherlands, and migrated to Canada in the 1950s in her 20s.

She is likely in the stages of early dementia, and one of the recommendations for dementia patients is to find music that they'd likely enjoyed as teenagers or young adults. I'd like to see if I can find something that fits that rough description. I expect I can make do with the English catalogue of classic rock and country from that time, but it'd be nice to find something a little different.

Can someone make any broad recommendations for popular Dutch music from the 1950s? Ideally, something I can find in mp3 format, but I'm willing to spend some money.