I just installed Xubuntu 20.04, and am currently working to get mp3/flac-support going. First, I did install various players to try the look & feel (Clementine, Rhythmbox, QuodLibet ...) & settled for guayadeque in the end (would have prefered gmusicbrowser, but, alas...)
Anyway: Guayadeque does play ogg, ape, most other formats, some (but not all?!) flac, but no mp3. I did install, purge and reinstall restricted extras & addons, but to no avail...
vlc and parole do play all, but those suck as music browsers! (I got a large collection of 70.000 songs, so I need extended DB-type search & other capabilities).
So: What to do, where to look?
Thank you very much for your suggestions!