12 major keys. If you’re looking at the key signature in the music staff, you can’t tell a difference between G and Em. They have the exact same notes. It’s just a matter of which of those notes dominate the song.
Wayfairing Stranger is an excellent example. Some say the song is in Am. Some say it’s in C. So the A part sounds like a minor song. Then you get to the B part and it shifts to major overtones. The key signature didn’t change. It’s just the notes primarily used in each section of the song that give it the feel.
Check this out.
