You can now group up multiple Echo's for music playback thanks to a new feature that Amazon has started to roll out to its Alexa software. The multi-room feature as Amazon is calling it, will let you connect more than one Echo speaker together and let you synchronize your music streaming so that it plays along on both speakers, or all speakers if you have more than two. This also works for the Echo, Echo Dot, and Echo Show, leaving no limitations on users in regards to which speakers they'll need for this new feature to be compatible.
While there are no limitations on the type of Echo device you need, there are limitations on the music streaming services which support the new multi-room sync feature. One of the biggest streaming services for example, Spotify, does not currently have support, Amazon does mention though that it will be coming soon alongside support for SiriusXM. Beyond those two, the currently supported services are Amazon Music, TuneIn Radio, Pandora, and iHeart Radio. If you stream your music from Google play Music, unfortunately Amazon doesn't mention if this service will eventually gain support, so you'll need choose a different service if you want to use the new feature.
Much like any of the other really cool features you can do with Echo devices powered by Alexa, the multi-room music syncing allows for voice-activated music playback once users have created a group. Creating groups of Echo devices can be done from the Alexa application and allows for at least two speakers to be connected, but it will allow more than two if you have more than two Echo devices in the home, and while this is being targeted as a way to play music in a synchronized manner in multiple rooms in the home, it's also a great way to get a surround sound-like experience for your audio if you place all the speakers in the same room before starting the playback. Right now Amazon says the new feature is available to Echo device owners in just three countries, which are the U.S., the UK, and Germany, at least for now. While the multi-room music syncing with Alexa is only available on the Echo devices at the moment, Amazon is launching a couple of new tools for developers that will allow other speakers powered by the Alexa Voice Service to integrate with it too, so support for speakers coming from third-party companies will show up soon enough.