Ooh I see now! I should have thought of it, most of my songs are in opus format, and tambourine is only picking up the flacs:
023-07-04 11:00:57.342 | ERROR | io.github.mmarco94.tambourine.data.Library | Error while parsing music file: No Reader associated with this extension:opus
My bad, many music apps don’t support opus. I have everything in flac on a separate drive, but there’s no room on my laptop so I convert them. Opus is open source and compresses files in a much more optimised way than mp3, so you can get smaller files with way better sound quality.
I have no idea how much work adding support for it would entail, but I would definitely use tambourine if you decided to do it. Right now I’m using Elisa on KDE, which is nice but very slow to recreate its database every time I add or change something.