The first reason is the domain: even rock bands usually have north of four people involved in a given song, and when you look to jazz tracks, the task of manual data entry becomes huge. Also, unlike with iPhoto (or Flickr or del.icio.us), there is no concept of a discrete “tag” for a music track—in iTunes or anywhere else, as far as I can tell. Everything must live inside an unstructured comments field. So each item must be added manually, and God forbid you want to remove a tag from more than one item.
I had created an AppleScript to cope with the first challenge, a simple script that puts a user-defined keyword at the end of the comments block. But in a recent MacOSXHints article and its comments, I was exposed to a host of other solutions and am convinced it will be easier for me just to adopt someone else’s approach.
I’m tempted by the approach of managing iTunes tagging with Quicksilver, but I have actually given up using Quicksilver as it tends to slow to a crawl on my 1GHz G4 PowerBook. The approach of Common Tater looks good, but I’d rather have a small atomic script than a monolithic application, and it hasn’t been updated in quite a while. TuneTags has the same objection, plus the fact that its XML-like markup is too big to fit comfortably inside the meager 255 characters given for comments on a track.
I look forward to checking out Christopholis’s TuneTag (no relation) and the Add/Remove Tags scripts from dwipal. But ultimately the AppleScript solutions will need to yield to either a cross-platform iTunes plugin with a consistent tag separator methodology (semicolons? asterisks? XML? <T>?) or to a dedicated tag feature implemented by Apple. I’ve never understood why iTunes never got tags and iPhoto has had them since the beginning.