One of the great features of OneDrive and Xbox Music on Windows (now called Groove) is that you can you can store all your music in OneDrive and then access it via the music apps online or offline for free. Microsoft have updated the iOS and Android version of Xbox Music adding the free music playback features. Previously you needed an Xbox Music Pass subscription to be able to use the iOS and Android version of the apps but now that restriction has been lifted.
All you have to do is copy you music collection in to OneDrive and then you can stream your music via the apps for free plus you can also download music for offline playback. You will still need a Groove Music Pass to be able to listen to music you don’t own but this update is a great feature and should bring new Android and iOS users to Xbox Music (soon to be called Groove).