Mp3Tag

In order to edit the descriptive metadata of MP3 files, a specialized tool is required and Mp3Tag is one of the easier to use tag editors.
Its main advantage is that it provides support for batch operations, which means that you can modify the ID3 tag information for more than one file with just a few clicks. Although lightweight, this application impresses through simplicity and functionality.
If you only need to edit the tag information of a single file, than the 'Single' mode is the one to go for. Otherwise, in case there are more files in the queue, the 'Batch File' mode must be selected.
The application displays the title, artist, album and the song genre, enabling you to easily edit each one of these fields, even though the input file is read-only. On the downside, there are more fields that the ID3 tag can contain (such as year, comments, composer, encoder, copyright, language etc.) and Mp3Tag only allows you to view the aforementioned ones.
In 'Single' mode, the application includes options for playing the song as you edit its tag data, while the 'Batch' window does not comprise this feature. On the other hand, when performing batch operations, you can also select an album art to assign to your MP3 songs.
An inconvenient of the application is the way it allows you to access its features. It does not comprise a single GUI for all the options and not having a 'Back' button to return to a previous step is really annoying.
While it could use some improvements to make it more accessible and allow you to edit more ID3 tag fields, Mp3Tag is a small utility that accomplishes its purpose with success. It provides you with an open-source alternative to more complex tag editors, which makes it worth a try.