Windows: We've talked about tools that automatically clean up your music library, but if you only need to edit a song or two, AudioShell is a Windows utility that lets you do it from Explorer, without opening a new app.
To be fair, AudioShell isn't a new tool, although AudioShell 2 is relatively new. We highlighted AudioShell ages ago when it was brand new (and brought to you by the folks behind Tag&Rename, another great audio tagging tool).
Since AudioShell is a windows shell utility, using it is as simple as browsing to where your music files are stored, right-click on it, and select "tag editor". You'll get a new window with the files metadata already populated (if there is any), and you can quickly make changes, add more data, swap out album art, and save the tag and see your changes. Best of all, you're doing this in explorer windows, without opening a new app, re-opening the files you want to edit, or waiting for a tool to load or files to be scanned.
AudioShell 2 is free, supports heaps of audio file formats, and available now in both 32 and 64-bit versions. Hit the link below to download it, and if you're looking to clean up your music library, you can do it automatically with a tool, or you can use our guide to whipping your metadata into shape manually.