https://www.gamespot.com/articles/microsoft-is-ending-groove-music-heres-what-you-ne/1100-6453734/

Given Microsoft's partnership with music-streaming giant Spotify, this was probably inevitable--and now it's confirmed. Microsoft said today that it will end support for its music service, Groove Music, at the end of the year. After December 31, 2017, the Groove Music app will lose of its core functionality, including the ability to stream, purchase, and download music. So basically all of the important stuff.

Microsoft is working with Spotify to ease the process. Microsoft will release an update for the Groove Music app that will allow users to move their collections and playlists to Spotify. This will be available to do until the end of January.