Mp3tag is a powerful and yet easy-to-use tool to edit metadata of common audio formats where it supports ID3v1, ID3v2.3, ID3v2.4, iTunes MP4, WMA, Vorbis Comments and APE Tags. It can rename files based on the tag information, replace characters or words in tags and filenames, import/export tag information, create playlists and more.
Mp3tag supports online database lookups from, e.g., Amazon, discogs, or freedb, allowing you to automatically gather proper tags and cover art for your music library.
+ Batch Tag Editing
Write ID3v1.1, ID3v2.3, ID3v2.4, MP4, WMA, APEv2 Tags and Vorbis Comments to multiple files at once.
+ Support for Cover Art
Download and add album covers to your files and make your library even more shiny.
+ Import from Amazon, discogs, freedb, MusicBrainz
Save typing and import tags from online databases like Amazon, discogs, freedb, MusicBrainz, and more.
+ Replace characters or words
Replace strings in tags and filenames (with support for Regular Expressions).
+ Create Playlists automatically
Create and manage playlists automatically while editing.
+ Rename files from tags
Rename files based on the tag information and import tags from filenames.
+ Export to HTML, RTF, CSV
Generate nice reports and lists of your collection based on user-defined templates.
+ Full Unicode Support
User-interface and tagging are fully Unicode compliant.
Besides these main features Mp3tag offers a variety of other functions and features ranging ranging from batch export of embedded album covers, over support for iTunes-specific tags like media type or TV Show settings, to combining multiple actions into groups that can be applied with a single mouse click.
Mp3tag : http://goo.gl/WEWB3
173 Sud (via Lifehacker)
MP3Tag actually lets you copy and paste multiple tags at once—just select one album, press Ctrl+C, then select the new album, press Ctrl+V, and you're done! You've copied over multiple tags for multiple files in just a few seconds. It made things a lot faster when replacing all those old albums.