Assuming all of your music files are stored in your Music folder, please follow these steps to remove your music files from RealPlayer.
1. Open RealPlayer.
2. Click RealPlayer logo on the top left and click Preferences.
3. Click Library & Device Sharing and under Watch these folders, click your music folder and hit Remove folder
4. Click Ok
Please note: If you have music files stored at a different location, you will want to remove that folder as well. However if these folders have your video files, they will also be removed. The best solution is to ensure all of your music files are stored in your Music folder.