You probably have a few dozen duplicate files, chiefly MP3 and photos in the Google Drive.
This is a handy tool that scans selected directories and finds any duplicate files inside them.
The app works with all sorts of files and can also be configured to scan sub-folders within a given directory.
You can make judgement yourself if you want to trash by selecting them.
Supports IE10+, Chrome, Firefox... Provides connect with Google Drive. You can directly scan duplicate files with your drive.