Another One Bites the Dust, for instance, is built on a drum loop. There was the main riff and a bunch of backwards piano notes, cymbal crashes and claps, some guitar fragments. Stuff everybody has in their sample library these days. It would be comparatively easy to build this thing today, if you had the right muse in the first place. The idea was less is more, and it worked pretty well. The band would have never contemplated going about recording in this manner, ever.