Apps like Mastodon, the open-source site that involves posting on a social feed similar to Twitter’s timeline, are tricky for most people to set up.
Mastodon is not difficult to join - provided you can find a server that's accepting new users. But it's probably difficult for people used to Twitter or Facebook, which are a single sites, to understand.
Still nothing under #folkmusic. Little under #music apart from people just linking to videos they like. But this on the servers I'm linked to; there may be servers full of informed music posts - but they don't appear on my site's searches - I'd have to know and follow individual posters.