If 3D effects and tilt controls weren’t enough to sell you on Amazon’s upcoming smartphone, perhaps a halfhearted streaming music service will do the trick. In the wee hours of the morning on Thursday, Amazon quietly launched Prime Music, a streaming service that has been tumbling around the rumor mill for more than a year. Prime Music is a free add-on for Amazon Prime subscribers, though the recent Prime price increase likely had something to do with its imminent arrival. With Prime Music, users can stream unlimited tracks from Amazon’s limited music catalog. According to the company’s website, Prime Music is currently home to 1 million songs. For comparison, Spotify, Beats Music and Rhapsody have music catalogs containing more than 20 million tracks each, and