Run Tunes Cleaner for Mac and click “Start to Clean iTunes” entry to scan iTunes music library.
The software will scan iTunes music files automatically. With it done, all music files with different problems will be displayed in specific categories at the left sidebar. You can choose each file to fix or just click “Fix All” button to fix all music files at a time.
Fixing progress may take some time. So you could click "Pause" button to pause fixing during fixing.
With fixing done, you can simply click “Apply” button to apply the fixed result. Moreover, you can fix some unrecognized songs manually. In addition, if you don’t want to fix the result right now, just choose “Edit > Save Project” in the program menu to save unfixed music files for next fixing.