Playing Spotify music on the Amazon Echo is now as easy as saying three words: "Alexa, Play Spotify." The e-retailer-slash-device-maker launched voice control for the app and two other music services in late January. But, you still had to stream music to the speaker via Bluetooth with a phone or a tablet. Now that Spotify is baked in, Echo can play music from the service directly. The catch? You can only take advantage of the feature if you have a Premium account in the US.