Hi, to play Spotify on Discord, you just need to link Spotify to Discord:
1. Install and launch the Discord app on your computer;
2. Navigate to the "User Settings" option and choose "Connection" in the menu on the left > "Spotify logo" button;
3. It will pop up a new window of "Connect Discord to your Spotify account", in which it requires you to confirm it and log in your Spotify account details. After that, you will see the Spotify app on the Discord connected list;
4. Now, you can choose to show your Spotify name on your profile or just as your status by clicking the "Display on profile" or "Display Spotify as your status" option.
When your Spotify account is connected to a Discord account, you can start to choose Spotify music for playback. It will be visible on both the mini profile and full profile that others can see it.
Of course, if you want to share and play Spotify music together without premium, you might as well need a Spotify song downloader. Such a tool helps you locally download Spotify songs to common audio files, so that you can use Spotify music on any player and device offline without hassle.