Google is offering new users a 4-months FREE trial of Google Play Music All Access Subscription (regularly $9.99/month) for a limited time. The service will continue after the four months at a rate of $9.99/month. be sure to cancel beforehand if you do not wish to be charged.

Google Play Music All Access lets you listen to any music in their catalog of millions of songs, ad-free. If you have your own tunes locally, they will match them in the cloud and will store all your music in one place.