When you think about it, considering the huge popularity of music videos on the platform and the fact that it has launched more than a few careers, it's surprising that YouTube hasn't already created an app just for tunes. But here it is (US-only for now) and it has some advantages over the bog standard YouTube app.

Music discovery, a la Spotify and its ilk, is a large part of the experience: you'll be greeted by recommended tracks and personalised stations while sorting music by live concert footage, cover versions, Karaoke-style lyric videos and remixes. A subscription to Red membership will offer the same but without ads. In addition you can listen to music offline and swap between video or audio-only mode. It remains to be seen how this might be integrated with Google Play Music; surely users wouldn't be expected to subscribe to both separately?

http://youtube-global.blogspot.ie/2015/11/a-youtube-built-just-for-music.html