I have not had any luck finding any Terminal or GUI applications that could get lyrics from MP3 ID3v2 tagged files. The only way I've found is to go into the info dialog (in iTunes) and copy the text there.
If you're looking for lyrics to several songs, or want and easier way to do this simple and useful task -- I love to do this because while I listen to the song, I can read the lyrics and control iTunes or leave it behind other applications -- you can use this AppleScript:
tell application "iTunes"
set these_tracks to the selection of browser window 1
set the track_count to the count of these_tracks
display dialog "Copying lyrics of " & (track_count as string) & ¬
" tracks." buttons {"Cancel", "Copy"} default button 2
if the button returned of the result is not "Copy" then
return
end if
set the item_counter to 0
set letras to ""
repeat with this_track in these_tracks
if letras is not "" then
set letras to letras & return & return
end if
set letras to letras & "==> " & the name of this_track & return & the lyrics of this_track & return
end repeat
set the clipboard to letras
end tellMac OS X Hints
http://hints.macworld.com/article.php?story=2006052104465643