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.

It also provides Shared File (owned by me) Finder, Orphaned File Finder (Not have a parent folder).

Supports IE, Chrome, Firefox... Provides connect with Google Drive. You can directly scan duplicate files with your drive.