If, like me (or you're me, trying to remember this), and have legacy mp3s organizes like this:

artist/album/song

but the mp3s aren't tagged, you can tag them like this:

find . -type d |while read d; do echo $d; find "$d" |grep mp3$|while read f; do echo " $f"; mp3info -a Autecture -l "$d" "$f"; done; done