Yes there's hold music, and yes there's <pink> noise for falling asleep (has a falloff), but in either case I personally don't think it should be on Spotify/another generic music streaming service.

Put a different way, if I'm listening to music on random, and Led Zeppelin finishes, do I want there to be a chance of pink noise or elevator music playing after that song? Not really, but if "it's all on Spotify," then it could happen