Up until now, if you wanted to play Spotify music on the Amazon Echo, you had to say the artist or song you wanted to play and then tack on "on Spotify" at the end. It's a little cumbersome, but now you no longer have to do that, as you can set Spotify as your Echo's default music provider.
By default, the Echo uses Amazon Music whenever you ask it to play a song, but after you set Spotify as the default music provider, you can simply say something like, "Alexa, play The Weeknd" and it will start playing it from Spotify instead of Amazon Music. The same thing works with your Spotify playlists as well if you say, "Alexa, play (playlist name) playlist."
To set Spotify as the default music provider on your Amazon Echo, start by opening up the Alexa app on your smartphone and tapping on the menu button in the top-left corner of the screen.
From there, tap on "Settings".
Scroll down and select "Music & Media" under "Account".
At the bottom, tap on "Customize my music service preferences".
Tap on the drop-down menu where it says "Amazon Music" under "My default music library".
Select "Spotify" and hit "Done".
Tap on "Done" again.
After that, you'll no longer need to tack on "on Spotify" whenever you want Alexa to play music from the third-party music service. You can still use Amazon Music when you want to by tacking on "on Amazon Music" at the end of a command, but by default, the Echo will use Spotify for now on.