These new tools enable device makers with connected audio systems to control music playback using Alexa. A customer can then use any Alexa-enabled device - for example an Echo Dot - to play music throughout their home on their connected audio systems. Amazon is excited to be working with leading brands on this offering, including Sonos, Bose, Sound United, and Samsung.
The company also implies multi-room audio will work in mixed environments, though it specifically mentions it for devices that use the Alexa Voice Service (AVS). It’s not entirely clear how multi-room audio will work if you have both smart and “dumb” speakers; so, for example, if you have a couple Echoes and a couple Sonos devices—which, as it happens, I do—will you be able to play the same audio across all of them, completely in sync? If so, that’s a pretty huge deal. I wonder if Apple will be able to get the same traction with third-party speakers working with the HomePod via AirPlay 2.
The synced audio for the Echoes themselves seems to be available today, though I’m not currently at home to test it. The third-party API is available to developers today, though it will probably not start showing up for users until later this fall.
[Update: Jason here. I am currently listening to “Hamilton” being played through an Echo, Echo Dot, and Echo Show, all perfectly synced—all from saying “Alexa, play Hamilton everywhere.” Pretty great.]