That is, all of these digital music management systems allow you to search for a song by meta data in text form — artist name, song name, album name, genre, date, etc. — but you still can’t find a song that you remember for its most fundamental characteristic: what it sounds like. Maybe it’s impractical to ask a computer to recognize the few bars of a tune that you can hum, but there must be some other way to identify a track you have locked in your head (I remember seeing plot-finders that allow you to find similarly remembered/forgotten movies a few years ago, but they seem to have gone away) — and anyway, why can’t you just hum into your computer? With speech recognition continually ‘just around the corner,’ this would seem to be an ideal use for it. Wouldn’t that be incredibly handy? Moreover, wouldn’t that be an effective way to sell more songs on the iTunes Music Store?