Changing the Tonality from C Major to C Minor transforms this piece from bright and happy to dark and sad…
Notice that the C major chord (I) becomes a C minor chord (i)… and that E (Mi) becomes Eb (Me), but the G7 (V7) chord remains unchanged…

Changing the Tonality from C Major to C Minor transforms this piece from bright and happy to dark and sad…
Notice that the C major chord (I) becomes a C minor chord (i)… and that E (Mi) becomes Eb (Me), but the G7 (V7) chord remains unchanged…