Amazon's Echo speakers have a ton of smart capabilities, but until recently, playing music from any service other than Prime Music required telling the device which service to use each time. Now, users may have noticed an option to set Pandora or Spotify as its default music player. If you have one of the Alexa-connected devices, then you can go into its control app on the web or a mobile device and look under settings to switch the default away from Amazon. Once it's set, just talk normally to the speaker, "Amazon/Alexa play (artists/song/etc.)" and it will play from the proper service.