http://www.newsweek.com/apple-music-spatial-audio-future-music-finally-1599177

Music mixed in stereo spans left and right to make use of our two ears, but music in Apple's Spatial Audio with Dolby Atmos adds more dimension to songs. As with anything in audio, it's much easier to "get it" by just listening to it. In this case, however, fully grasping it comes when you stop listening to it. Because Spatial Audio makes music sound more natural and immersive, it's less about stepping into the world of Oz, where everything becomes colorful in an instant, and it's more about never wanting to step out of this world back into a colorless, flat one.

APPLE

Spatial Audio creates depth and room for the music to breathe and be arranged in potentially new ways. Initially, this technology is demonstrated by not just shifting between left and right but by the sound's having the extra front and rear dimensions to surround you even better. To fully experience its benefits, press play on a Dolby Atmos song and then, while it's going, head to the iPhone's settings and, under music, turn off Dolby Atmos to go back to listening in stereo. The singer and all the instruments instantly become rigid, flat and too close. A stereo mix now almost feels like looking through a glass window where the artist is pressing their face against it, trying to get unnaturally close to you.