Preferred speakers are speakers selected as the default speaker in a Device group. If you have created a Device group with an Alexa-enabled device, all you have to say is, "Play the Beatles." Alexa starts playing music on your preferred speaker, no matter which one is closest or which group it's in. If no preferred speaker is selected in a group, music only plays on the device that heard your request. You can choose a preferred speaker in your Device group from the Alexa app.