id3ed is an ID3 tag editor for mp3 files. You can set tags interactively or from the command line, or a combination of both. id3ed can set genre by name or number. You can also remove or view tags.
http://www.azstarnet.com/~donut/programs/id3ed.html
MP3info is a small utility for reading and writing MPEG Layer 3 (MP3) ID3 tags. Console (command-line and interactive ncurses) and GTK versions are included.
http://metalab.unc.edu/mp3info/