LOS ANGELES (AP) — If you were going to reinvent MTV for a mobile generation, you'd probably come up with something like YouTube Music. It's a video-first music service that also plays in the background like you'd expect a music app to do. That sets it apart from other music apps out there, many of which give you a choice of videos or songs, but not interchangeably.

Source: Yahoo Music
Link: YouTube Music is a great music-video app _ if you pay up