Q: and the difference between playing in a minor and major key?
A: explaining this is like explaining the difference between a happy face and a sad face. it's not always possible to explain the difference, but you can just sense it. and of course some songs play tricks on you and kind of use both. other songs are very clear about it. jingle bells is major. "stayin alive" by the BeeGees is minor. generally, in a major key song, the "1" chord (sometimes called the "root" chord) would generally be major. and in a minor song, the "1" chord would generally be minor. now, how do you know what the root chord is? again, it's similar to knowing which side of someone's face is the top. how do you recognize this when a person is lying on their side? i have no idea, but you just know somehow