https://techcrunch.com/2017/12/13/amazon-echos-multi-room-music-streaming-feature-now-supports-spotify-and-siriusxm/

Just in time for all of those ridiculous holiday playlists, Amazon’s added two key players to the Echo’s multi-room streaming feature. Spotify and SiriusXM now join the ranks of TuneIn, iHeartRadio, Pandora and, naturally, Amazon’s own Music Unlimited service.

The feature, which hit the smart speakers over the summer, makes it possible to stream songs to multiple Echos on a single network. It’s also possible to play music on individual devices in various parts of one’s home, by telling Alexa to “play my music” and then specifying the a location. So, you know, like, “Alexa, play The Kinks on upstairs from Spotify.”