EasyTAG

It would be great if you could do things like this:

if(%y, "%y-","")%a/%b if(%d,"(disc %d) ","")/%n-%t

This would allow you to rename an entire collection without needing to know
whether you were dealing with a multi disc recording, or whether a
particular tag that you'd like to use was missing or not. The results of
the rename would still be consistent within the constraints of the data
available.