1. Click the Notifications icon (bell icon) in the top-right navigation panel of your account.
2. Click the Settings icon in the top-left of the dropdown - this will open up your Notification Settings.
3. Locate the Catalog section and scroll down to Folder events.
4. From here, you can adjust how you would like to receive notifications when someone adds or removes a song from a shared playlist folder.
Click the drop-down menu associated with that setting to choose whether or not you want to receive notifications and how you'd like to receive them.
Off: You will not be notified in any way.
Notification: An in-app notification will be triggered (check out Understanding your activity feed to learn more).
Email: You will be notified via email rather than via an in-app notification.
Email, Notification: An email and an in-app notification will be triggered.