Minor vs. major keys

[SueMartinez]

How do I explain to a non-musical person what the difference between a song written in a major or a minor key is???

[j2buttonsw]

major = happy, minor = sad (flattened 3rd)

[LoFatSpred]

More precisely, Flat 3rd, Flat 6th, and Flat 7th if you're dealing with the Natural Minor key (as opposed to Harmonic Minor which more traditional music is built on). Each degree or note of the scale has a chord constructed upon it. In the Major scale, up to the 5th degree (the most commonly used region in pop music) these are as follows: maj, min, min, maj, maj. In the Minor scale, these are reversed ie min, maj, maj, min, min. There literally are more minor chords in a minor key and more major chords in a major key, and as yer man says above, generally, min = sad, maj = happy, although this is a bit broad. Some of the most joyous music I've ever heard has been written in a Minor key, so it's not foolproof. Music eh? it's a ******' lottery.