“Every year, a handful of songs do much, much better than all the others, and nobody has much idea why. If the hits only did a little better than the non-hits, this unpredictability wouldn’t matter. But that’s not how it works. Only about one-fifth of artists end up making money for the label, and a few make so much that they subsidise everyone else, but you can’t tell in advance which ones will do well.” But new software hopes to have cracked the hit code.