As silly and schticky as this video is, for me it represents a very cool and important music theory concept to understand. Stevie does a quick crash course on major vs. minor at the beginning (although solfege in the minor scale is Do Re ME Fa Sol LE TE Do) and I had fun guessing what the melodies and chords would be when he changed the songs over to a minor key. The thing is, there’s actually some important wiggle room and interpretations you need to make when transposing something like this.
For instance, Stevie mostly went to the parallel minor, rather than simply changing the harmony to the relative minor and leaving the melody alone. His Police cover went full on black metal with all minor chords that didn’t come from any particular key, which was a cool sound. I recommend trying something like this yourself – it’s really a great exercise.