Xbox Music Offering 15-Song Trial on Xbox One, No Ad-Supported Version
On top of the monthly subscription for Xbox Live Gold, you will also need to pony up $9.99 (USD) a month for a Music Pass if you want to hear some sweet tunes.
On the PC, there is an ad-supported version of the Music Pass that lets you listen to music with an occasional ad interjected here and there, much like Spotify does. On the Xbox One, there will be no such free ad-supported version. You either pay or you don't get to use it, it's as simple as that.
That is rather unfortunate, especially when you're already paying a monthly fee.