The circle of fifths is one of the most fundamental and useful concepts in music theory. It can be used for many purposes; learning major and minor scales, the order of sharps and flats, building major and minor chords, chord progression, understanding keys and the accidentals that occur in keys.
In this article I’m going to discuss how you can use the circle of fifths to play the two most common progressions in western music in any key. I’m referring, of course to I-IV-V progressions which are the most common chord progression in rock, folk and country music (examples include: “Brown Eyed Girl” by Van Morrison, ” Down on the Corner” by CCR and “This Land is Your Land by Woody Guthrie” ) and ii-V-I progressions which are the most common progression in jazz and also common in all western music genres. (examples include “Satin Doll” by Duke Ellington, Ella Fitzgerald’s “How High the Moon” and Gershwin’s “Summertime”. )
To figure out any I-IV-V progression:
1. Pick the key you’d like to play the chord progression in. I’ll arbitrarily choose the key of D which is at two o’clock on the circle of fifths.
2. To find the IV chord simply go counter clockwise by one hour. Relative to a root note of D, one hour counter clockwise is G.
3. To find the V chord simply go clockwise by one hour. One clockwise hour past our root note of D is A.
I-IV-V in the key of D = D-G-A
And there you have it, it’s that simple! To reiterate, to calculate what a I-IV-V progression in any key is you pick a root note then go one hour backwards to find the IV chord then go two hours clockwise (or one hour clockwise from the root) to find the V chords.
To figure out any ii-V-I progression:
1. Pick a key to play the chord progression in. We’ll use the key of A for the example which is at three o’clock on the circle of fifths.
2. To find the ii chord go two hours clockwise relative to the root note. Our root note A is at three o’clock and two hours past three is five o’clock and on the circle of fifths five o’clock is B.
3. To find the V chord go one hour counter clockwise from the ii chord. The ii chord (B) is at five o’clock and one hour counter clockwise from five is four o’clock so the V chord is E which is at four o’clock.