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This is a pretty low effort question, you know about F-Droid ....so use the search function.
Some examples are funkwhale (for playing self-hosted content), or MusicPiped which seems to fetch from youtube.
For results on F-Droid app you can click "about" and then "source code" which normally links to the projects github page
They also have UltraSonic if wants to use servers with Subsonic API.
NewPipe does a great job. It uses YouTube's library which includes YouTube music.
I use an instance of InvidioUs to stream YouTube music.