I do see that others have had the same problem, but I have not found a solution. The songs appear, but there is no audio, and yes, I have checked the whole volume thing and done a reinstall. I have Quick Time and iTunes and Windows Media Player also, but I don't want to have to switch out of Spotify when I want to listen to my own music. I pay for Unlimited, and had my music before! Please don't make me cancel my subscription; I am about to as this is so frustrating. I have better things to do with my time than troubleshoot a service I am paying for!
This is for itsie, who gave me kudos for my comment of frustration about Spotify's new design in 2014. Kudos not really deserved, because by updating my QuickTime, the files were recognized! But thanks; it was indeed a trial of frustration followed by a Homerian "Duh!"