Installing :

 apt-get install id3tool 

To see the current metadata for an mp3 file:

 id3tool <filename.mp3> 

Here is the command I used to update quite afew mp3's:

 id3tool <filename.mp3> -t "<song title>" -a "<album name>" -r "<artist name>" -y "<year>" -c <track number, no quotes, just the number, like 1> <filename.mp3>