‘Coquillo’ is an open source audio metadata editor that runs in GNU/Linux and MS Windows platforms. Tools like these are useful, because sometimes audio files might contain wrong or empty data, under fields like ‘artist’, ‘album’, ‘genre’ etc and since it’s the ‘metadata’ that holds these information, you can use something like ‘Coquillo’ to fix them.
‘Coquillo’ doesn’t support a huge number of formats, but, if having the support for MP3, FLAC, Ogg and MusePack is enough for you, then this is a pretty decent utility. You can mass edit files and load as many as you want (as long as they’re in the same directory), but it doesn’t seem to support drag-n-drop though (it didn’t work in Ubuntu anyway).
Also supports manually inserting an album art image (including changing its size), search ‘CDDB’ (online database for audio tracks and albums) for finding and filling matadata fields automatically, change the start-up directory, makes it automatically ignore certain words or text and few more options are available via its ‘Settings’ windows.
It has built in packages for both MS Windows and a lot other GNU/Linux distributions (Ubuntu, Debian, Arch, Mandriva etc), so please visit this page and then choose your preferred OS and download the proper package.
As always, if you’re using Ubuntu (supports 11.04, 11.10 Oneiric Ocelot and 12.04 Precise Pangolin) then once the download completes, double click on the ‘.deb’ file and follow the instructions of Ubuntu Software Center to install it. Good luck.