If other users leave comments on your songs that you don't want, you can delete them. Long press on the comment (Android) or swipe left (iOS) to bring up the delete function.
If a user repeatedly leaves unwanted comments on your songs, you can block them. Go to the user's profile and tap the three dots next to the ‘Follow’ button (Android) or in the navigation bar (iOS) to open the menu. Select ‘Block user’. Users you have blocked can no longer leave comments on your songs or follow you.
You can unblock users at any time if you wish.