On the Woodstock performance, you can hear this as he's winding down from Voodoo Chile, just before he gets into the beautiful slow Am thing (Villanova Juntion). I've heard other instances of this, it's a move he pulled some of his compositions from. I don't know what it is, he'll play a bass note, then chord, then bass note, then chord etc., and he's cycling through some sort of thing, going up and down in 4ths? 5ths? I can't figure out what the theory is behind it or what it is. But it's great, always loved it, now I'd like to know what it is.

Does anyone know what I'm talking about? Corleone? Or any other of our resident scholars? Thanks!

I don't have the song you're talking about. But it could be some ii V changes. Or, it could be cycling through the circle of 5ths. Like the chord progression of "Hey Joe".

Someone sent me a clip. I was remembering the wrong section. and I've seen tapes of him doing this from other performances, etc., but this at least has a couple of short examples. On this clip as timed on Youtube, he does it at these points:

3:38-3:41
6:05 - 6:12

http://youtube.com/watch?v=so1ntxVyZ2c&mode=related&search=

Yeah, it looks like he's playing through the Circle Of Fifths.

Jazz tunes often use the Circle to change keys. So the Circle is also called the "Cycle Of Keys".

The most common move in Western harmony, is the V going to the I. In the key of G, that's a D moving to a G. There is 1 more major chord in a major key. It's the IV. So, you often hear about I IV V chord progressions. These are also called the TONIC (I)-SUB DOMINANT (IV)-DOMINANT (V). That's why V chords are often called DOMINANTS. These 3 chords (I IV V), form the basis of Western harmony.

Here's the interesting part: G to D is a 5th. But D to G is a 4th. 4ths. and 5ths. are pretty interrelated.

If you go clockwise through the Circle Of 5ths., you move in 5ths. If you go counter clockwise through the Circle, you're moving in 4ths.

Since these chords are so interrelated, you can move through them easily, and the listener accepts these "logical" sounds. If you keep moving in 4ths. or 5ths., you will eventually be moving into new keys.

EX: Starting in G.

If I move from G to D, I can be in either the key of G or D. If I move clockwise again, I arrive at A. A is not in G! So now, I'm either in D or A. Move clockwise again, and I'm now in either A or E. So, you can take it out farther and farther, until you eventually return back at your starting point.

So, this makes a smooth and logical way to present a key change.

Hey Joe's chord progression goes: C G D A E E. This is moving in 5ths also.

Jazz tunes often "Backcycle" through the circle, in 4ths. (Counter clockwise).

EX: C F Bb etc.

This works especially well, as you can think of C as the V, going to F as the I. Then the "key change", you picture F as the V of Bb. So, backcycling can present the most common move: V goes to I.

Let me know if this helps, or not.

Yup, that helps a ton. I know some of this by now, but knowing it in theory and being able to apply it or analyze with it, are different things. I thought he was cycling through something or other. I just loved the openness of what he was doing, since the keys are changing constantly it feels very open to me. Thanks Swain!

Glad to know it helped. Let me know, if you have any more questions.