Finding photos is simple; you just work out what tags are relevant and then form a search query out of them: get me all photos taken within Balwyn featuring my two sisters, myself and a wheel of Brie—but no possums.  If you’ve been prudent with your tagging when you add photos, this works perfectly every time.

I wish the same could be done for music.

So MP3s have ID3 tags, and any decent music software will recognise these.  But they’re not totally arbitrary; you get to store an artist, an album, a title, a genre and some other crap.  If you want to associate something else to an MP3, like “this was a favourite of mine in 2008″ or “this song features Ethiopian lyrics,” ID3 tags won’t help you.

But playlists might.

Let’s say you had a bunch of playlists set up to signify such things, like 2008 Favourites, Ethiopian Lyrics and Never Play These Automatically.  You could then easily inspect these lists to see what songs fall under these criteria, and you could double-click a playlist to listen to them.

Playlists are more of a one-way relationship though.  A playlist points to songs within it.  Existing software, to my knowledge, doesn’t look at a song and tell you the playlists to which it belongs.  Therefore, you couldn’t pick up a song in your collection and automatically be told that you stole it from Dan, it hails from Mongolia and it should always automatically be copied to your car’s music player.  Which means that when you identify a song as satisfying a certain criterion, you can’t easily know whether the appropriate playlist already reflects this.  So you unconditionally add it anyway, and because they’re lists and not sets, your playlists then contain repeated entries.

Authors of some software recognise that most people want this in a more limited sense: ratings.  They then all go about their own way in storing some number of stars alongside each song in one’s collection (it certainly doesn’t seem to go into the ID3 tag).

To me though, such a rating system is pretty useless.  Sure, I could default all my tracks to 3 stars and assign one star to anything I never want to hear but don’t have the heart to delete.  But would I do anything else?  If I started assigning four or five stars to songs I really like at this point in time, what happens when my tastes inevitably change?  The ratings aren’t going to be constant.  I’ll just be twiddling with ratings all the time.

And when I’m looking for songs in Amharic, besides searching for a few obvious artists, ratings certainly won’t help.

I wonder if I’m the only person who thinks this way—that tags could be applied to so much more than just photos—and if not, how long it will be before they can be used elsewhere.