If you don't mind switching to Tidal, you can do that with Plex. Otherwise, I don't think it's possible.
Like another commenter said, Mopidy can do it all in one instance. It works, but I personally find its integration with MPD clients to be a bit clunky so I don't use it all that much.
Personally I use Snapcast as an endpoint, plain MPD for local files, and navidrome for remote access to my library.
Snapcast supports Spotify endpoints, so I just switch to my Spotify stream when I want to listen to Spotify and to my MPD stream when I want to listen to local stuff.
This is more of an ecosystem than a single solution though, so it may not be what you're looking for.
Volumio can do this with the right plugins, but it's a bit janky and not as seamless as mopidy
A place to share alternatives to popular online services that can be self-hosted without giving up privacy or locking you into a service you don't control.
Rules:
Be civil: we're here to support and learn from one another. Insults won't be tolerated. Flame wars are frowned upon.
No spam posting.
Posts have to be centered around self-hosting. There are other communities for discussing hardware or home computing. If it's not obvious why your post topic revolves around selfhosting, please include details to make it clear.
Don't duplicate the full text of your blog or github here. Just post the link for folks to click.
Submission headline should match the article title (don’t cherry-pick information from the title to fit your agenda).
No trolling.
Resources:
Any issues on the community? Report it using the report flag.
Questions? DM the mods!