You can follow hashtags on Mastodon. So if you want music recommendations you can follow #NowPlaying, (for example) and every time someone uses that tag it’ll appear in your timeline as if you follow that person. It’s nice for follow discovery too, because if the same people keep posting links to tunes you dig, then it’s a fair bet that you’ll have similar interests.

I’ve not tried it myself, but I guess that in theory, you could follow a bunch of hashtags without ever following an actual account.