Watch the The Modes online guitar lesson by Robben Ford from Chord Revolution: Foundations
I'm going to play the chord progression to the vamp of a song of mine called "Freedom" from an album called "Tiger Walk", and this is actually in the key of G if you were to be quite literal about it. The chords that we use here are coming straight out of the G major scale. But a G is never played in the vamp. I'm playing other triads from the scale, but never a G. So what key is this song in is actually a good question. First chord is a C, next chord is E minor, A minor to B minor. I'm going to say the song is in the key of E minor, but we're playing a G major scale. G major and all the triads, or the triads of the G major scale. Sounds like this.