Pick tags, get an audio playlist — built live by everlitPlaylist.js
Playlists are immutable, keyed by their rule-set: identical selections resolve to the same canonical playlist for everyone (open this page in a second browser and pick the same tags to see the playlist ID match). Changing anything just resolves to a different playlist, so a saved or shared player can never change out from under its audience — while its tracks keep refreshing as new content matches.