I believe in FOSS to the point that I often unnecessarily uninstall mysql for mariadb.

With that said, I hate to be the guy w/ a non-FOSS recommendation but my suggestion, Symfonium (a paid app that has a free trial), does have a way to get the full version without Play Services.

I use it for online radio and it also lets you add descriptions/tags you can filter stations based on the tags for if/when your list gets long. And the online radio isn’t even the most popular feature for most users:

• Completely reconfigurable layouts
• Completely customizable ‘Now Playing Screens’
• It’s just one dev and he is VERY responsive to feedback (perhaps overly as he chimes in on most negative reviews on Play Store) and has built out various features based on forum suggestions/bug reports
• Smart playlists: For example they have Favorites, Recently Added, Most Played, Random, Rediscover. And all of these can be further split by Album/Artist/Playlist/Track
• It is integrated w/ my server running Jellyfin, so I can play music across all my devices and allows you to cache/download content for offline playback but otherwise allows you to stream over LAN

There’s too much to cover about it w/o sounding like a shill. Here are some people that aren’t me w/ their opinions:

• https://reddit.com/r/selfhosted/comments/17lyd3j/dev_symfonium_music_player_cast_the_self_hosted/

And here is an update on changes posted by the dev last week:

• https://reddit.com/r/selfhosted/comments/1jb6kiz/long_overdue_symfonium_update_thanks_for_the/