From their README


Contains an Alfred App workflow for managing Spotify. To import this workflow simply download it and double click it to install it into Alfred. Once installed you have two new commands available in your search bar.

For more information, please read the blog about this workflow on Medium:

Controlling Spotify

Type .s to activate the Spotify controls.

Spotify Controls

When selecting .sl for Playlist, you will be greeted by a list of Playlists you have entered in the appropriate node in the workflow. After installation, you should take a little time to change this list to contain your favourite playlists.

Controlling Volume

Type .v to activate the Volume controls.

Volume Controls

Please be aware the BLEEDING EARS option was mostly added as a joke. It is REALLY LOUD when you're wearing headphones. Please be careful with your ears and I will not be responsible for any damages inflicted while using this workflow.