Manage and update mp3 tags with Mp3 Id3V1V2 Tag Edit
Mp3 Id3V1V2 Tag Edit & Sort Tool is a free and powerful program that reads and writes all mp3 tags.
It can also clear all tags of mp3 files automatically in one or many folders; Restore from backup the tag data; Copy of edited mp3 files with advanced renaming options; Rename of edited mp3 files with advanced options, and more.
The interface is not flashy, and rather complicated, but the program works.
Read the help file first to make sure you avoid mistakes.