Not every song is a smash hit, and for every Katy Perry, there are thousands of Justin Guarinis praying for some attention. At last count, there are around four million songs on Spotify that haven't even been played -- which is why some kind soul has created Forgotify. Simply head to Forgotify.com, click the start listening button and the web app will randomly pick one of the unloved tracks to play. Voila! New music you probably never knew existed. If the outfit's estimates are accurate, you could go a long time before hearing something even remotely well-known, but be warned -- some of these songs were probably forgotten for a reason.