You never knew Björn & Benny, Agnetha & Anni-Frid had a progressive rock side did you? Here they team up in a large plexiglass pyramid with the `Floyd and Welcome you to the Master Scene, the Voulez Vous Machine, sil vous plait. (My pre-GCSE French is failing at this point monsewer).

Actually disco and prog did crossover, usually via Alan Parson's Project and naughty Italian disco bootlegs and a few strange Mike Oldfield disco covers (yes stranger than Pink Project).

Even Soft Machine had a go? As did Can and of course famously Pink Floyd themselves.

ABBA - Voulez Vous
Pink Floyd - Welcome To The Machine