[dude_abides]

1. Start with any key.

2. Look up the relative minor.

3. Go one step to the right and/or one step to the left in the Circle of Fifths. http://en.wikipedia.org/wiki/Circle_of_fifths

There, you have the most popular and pleasant-sounding chord progressions in any key. If you want funkier progressions, go further in the circle.

Edit: The chords sound more jazzy when you go counter-clockwise (it is the circle-of-fourths). Thanks for the correction, @gnaritas.

[gnaritas]

The circle of fifths and fourths are the same circle. Clockwise is a fifth, counterclockwise is a fourth.

[haberman]

It's more like it's a circle of both fifths and fourths, in both directions.

For example, C-G is a fifth if you go up, or a fourth if you go down. C-F is a fourth if you go up, or a fifth if you go down. So it can be a circle of fourths clockwise or counterclockwise.

[gnaritas]

Circles don't have up and down. :) Going clockwise is always a fifth, counterclockwise is always a fourth.

[haberman]

Circles don't, but intervals do. If you start at middle C (C4), you can go up to G4 to get a fifth or down to G3 to get a fourth. Ergo C-G can, in the abstract, be thought of as a fifth or a fourth.

I think what you are trying to say is that going clockwise gives you successive dominants, while going counterclockwise gives you successive subdominants.

[gnaritas]

> Circles don't, but intervals do.

Great, but we're discussion the circle of fifths and fourths, not the intervals. You've moving the goal post. A fifth and a fourth are the same interval, but in the context of a key they are not, thus the circle is only fourths in one direction. You can't decide if an interval is a fifth or a fourth without knowing the key.

> I think what you are trying to say is that going clockwise gives you successive dominants, while going counterclockwise gives you successive subdominants.

I'm not trying to say it, I said it.

Pick any note on the circle, it's fifth (dominant) is directly clockwise and it's fourth (sub-dominant) is directly counterclockwise. Counterclockwise is always the fourth of the note you're moving from.

[philbarr]

> The chords sound more jazzy when you go counter-clockwise (it is the circle-of-fourths)

As a side note, movement by fourths sounds more jazzy or "warm" because the interval of a 4th is itself a "warm" sounding interval. So if you want a warm sounding chord, slap a 4th in there.

In practice this often means adding an 11th (an octave above). So let's say you have a standard C7 chord (C E G Bb), if you want to make it sound jazzy/warm then add the F above.

If you want to demonstrate how warm a 4th is (or to get the feel for any interval) stack them up and play them together - C F Bb Eb

[jkmcf]

That might be the clearest explanation of the circle I've read.