Is there any piece of software that can help a degenerate like me fix my MP3 collection to not be such a fucking messy nightmare? Paid or free doesn't matter to me.
It sounds like MusicBrainz Picard would fit your needs well. It can do acoustic fingerprinting to find tags for poorly tagged files, it works on all major OSes, and it can organize your music folder pretty much however you want it to. The one thing I think it's not great at is album art but there are plenty of tools to handle that
I can't help, but there are a bunch of other comments in this thread throwing out software names that I've never heard of before today. Bound to be something!
I assume your problem is with the metadata? Just search for a "free mp3 audio tag tool" or similar and you should be able to find several options. Some of them might only do 100 tracks for free but there are workarounds. I've used several of them but it's been years. Nowadays I just rip all my own CDs into .flac with EAC or ABCDE depending on which computer I'm using and let it do the tagging for me.
If you're looking to fix metadate musicbrainz Picard would be my go to one. It's Foss and an good at what it does. Though I'd always recommend keeping an eye on it as sometimes it can start thinking rad on singles are are best ofs and not the albums they're on making a mess of things.
Unfortunately I don't know of any easy way to do that. Mine is all meticulously structured by hand like c:/music/artist/(year)album/01-trackname but then I mostly have full albums these days and not a lot of individual tracks.
It's also useful to use a metadata editor to remove all the "x artist featuring y" because media players will often read these as separate artists, which can get very messy very fast. Personally I just remove the "featuring" part entirely but if you must have it at least include it in the track title instead of the artist.
I think the poster above is referring to one that does it automatically. I don't remember what I used but I had all four letters filenames after pulling my mp3's from an iPod after my computer crashed. Found a program that basically interpreted the actual song rather than relying on metadata and it fixed all those files for me.
You certainly can but it would take ages for more than a handful of tracks. It's not practical when there's been automated solutions around for two decades already.
I use Ear Tag as a simple metadata editor for music files. Or Rhythmbox as a desktop library manager. Czkawka is good for weeding out duplicates and empty files. If your tracks have metadata for title, artist and album it's not the end of the world if the songs aren't properly sorted into folders.