OK, first of all, this: there are four million songs on Spotify that nobody has ever listened to. That is a pretty crazy number, and it’s about 20 percent of Spotify’s entire library. It’s also a hipster’s Candyland. Just think of it. Millions of obscure songs from unheard bands, just waiting for you find them before they’re cool. And Spotify just made it a lot easier by releasing an app called “Forgotify.” It creates a randomly sorted playlist of Spotify’s unloved songs, and you can comb through them to your heart’s content. Obviously, a lot of it could be garbage but, who knows, you might just get credited with discovering 2014’s breakout artist. But if you do, best to keep it to yourself. No sense in bringing a cool band to the mainstream …