If you're talking about streaming your own music, you could set up Jellyfin and then do all of the work to safely put it behind a reverse proxy and access it remotely.
It's a lot of work though, and you don't get new music. Still, that's about as good as you're going to get if you want a legal FOSS option (others have posted illegal options if you're looking for that.)
Navidrome is also a nice self-hosted option for music streaming. I recently cancelled my Spotify subscription in favor of hosting my own music library on it.