This is an excerpt from the four string banjo mailing list done by John Klehr.

  After it was posted there were numerous postings from people who felt that this was the best explanation of the circle of fifths that they had ever seen. I decided that it should be shared by all.

The Circle of Fifths and Chord Patterns

Home

Diatonic Scale 1 -W- 2 -W- 3 -H- 4 -W- 5 -W- 6 -W- 7 -H- 8

Do Re Mi Fa So La Ti Do

Key (Signature)

C (No #">

This is an excerpt from the four string banjo mailing list done by John Klehr.   After it was posted there were numerous postings from people who felt that this was the best explanation of the circle of fifths that they had ever seen. I decided that it should be shared by all.   The Circle of Fifths and Chord Patterns Home         C           F   G       Bb       D   Eb           A   Ab       E       Db   B           Gb/F#         Diatonic Scale 1 -W- 2 -W- 3 -H- 4 -W- 5 -W- 6 -W- 7 -H- 8 Do Re Mi Fa So La Ti Do Key (Signature) C (No #, No b) c d e f g a b c G (1 sharp) g a b c d e f# g D (2 sharps) d e f# g a b c# d A (3 sharps) a b c# d e f# g# a F (1 flat) f g a bb c d e f   Diatonic scale (normal do-re-mi…) has a pattern of spacing between scale notes of -W-W-H-W-W-W-H- ( or the spacing expressed in the number of frets between notes -2-2-1-2-2-2-1-) Circle of Fifths CLOCKWISE (Moving up) : C scale the fifth note is g G scale the fifth note is d D scale the fifth note is a A scale. fifth .. e   Also in F scale fifth note is c Hence the name "Circle of Fifths" - Recall Tenor banjo is tuned in fifths CGDA In a tune the chord pattern usually starts with and ends at the Home or Tonic (the name of the KEY the tune is being played in.) The simplest tunes contain only two or three chords C F G or the I (one) IV (four) V (five) chords. (Musicians use Roman numerals to indicate the chord name based upon it’s numbered location within the home scale. This enables keys to be changed without having to redefine the pattern. For example in G the I - IV - V chords are G C D). The exact pattern of this toggling between C F and G depends on the song but many folk songs, bluegrass, country songs and Christmas carols use only the I –IV- V chords. Good for beginning ear training. When told that it is a I –IV- V tune you start on the I (C chord) and when you hear the harmony change you’ve got a fifty percent chance of it being either a IV (F Chord) or a V (G Chord). Pretty soon your ear will tell. You get a real good clue when it is a I –IV –V7 pattern, because the V7 (G7 chord) always wants to resolve (lead you ) back to the I (C chord). Think of living on the "Circle of Fifth’s Street" and of course your home is number I. Your next door neighbor up the street is V and the down street neighbor is IV. I –IV – V tunes are like visiting your neighbors to gather the cups of sugar and flour you need to bake this tune. Your travels might be I IV I, I V I, I V I, I IV I. Each visit or travel could be considered a "Tune Fragment ". Any repeating tune fragment or phrase could be labeled with a letter and the total pattern consisting of all the labeled Tune Fragments we call the Tune Pattern. The chords to a tune consist of patterns of embedded and/or repeating patterns. Five Foot Two is the best example of a pure Circle of Fifths tune in an AABA Tune Pattern. In the key of C it goes : 1) [A Part] C E7 A7 D7 G7 C - You start at home and Jump up the street to the E7 Chord then you come down the Circle of Fifths House by House until you return Home. 2) [A Part] C E7 A7 D7 G7 C - You repeat the pattern 3) [ B Part] E7 A7 D7 G7 - "Bridge or Release" – Again a Circle of Fifths 4) [A Part] C E7 A7 D7 G7 C - Repeats first chord fragment pattern Side by Side is another AABA Tune but the tune fragments have different chord patterns A] C F C C F C F Fm C A7 D7 G7 C - A couple of I – IVs and a I –IV-IVm , then a Circle of Fifths jump up and resolve down. A] C F C C F C F Fm C A7 D7 G7 C - Same thing B] E7 A7 D7 G7 - Circle of Fifths jump up and resolve down A] C F C C F C F Fm C A7 D7 G7 C - Repeats first chord fragment pattern In Four Leaf Clover the pattern is changed enough to call it a [C part] : A] C D7 G7 C - Small Circle of Fifth’s jump and resolve B] A7 D7 G7 - Bigger Circle of Fifth’s jump and resolve A] C D7 - Partial C] F Fm C A7 D7 G7 C - IV- IVm –I , Circle of Fifth’s jump and resolve   The Chord Pattern Fragment C – C7 – F – Fm (or I – I7 – IV – IVm) is everywhere: Twelfth St. Rag, used as an ending, all over the place.       Now that you’ve got all that consider these points: When you travel Counterclockwise on the Circle of Fifths you are moving down in fourths (resolving). The chords on the Circle of Fifths may be minors or sevenths or a combination of minors and sevenths. Minor and neighboring sevenths can toggle as in the bridge to Sweet Georgia Brown. The "Chromatic Run Down" C7 B7 Bb7 A7 is used to set up a subsequent Circle of Fifths resolve down. (D7 G7 C ) as in Up A Lazy River and it’s tag. Although we have been talking in the Key of C – the Circle of Fifth’s works in all keys. In Eb as the Home, the " Chromatic Run Down and Circle Resolve" pattern would be: Eb7 D7 C#7 C7 - F7 Bb7 Eb Conservation of energy, or movement, or thought: It only takes two seventh chord Fingering Patterns to run all the way around the circle of fifths. Fingering Pattern #1 resolves to Fingering Pattern #2.which resolves to Fingering Pattern #1 moved down a whole step (two frets). Play an E7 up the neck followed by the closest A7 pattern down the neck. Repeat the fingering pattern used for the E7 two frets down and you’re playing the nearest D7 as you move down. G7 follows. Let your fingers do the thinking for you. Practice this the whole length of the neck. The Chromatic Run Down and resolve only takes two nearby fingering patterns for sevenths and a fingering pattern for the major resolve. The tenor banjo is tuned in fifths so if you move a chord fingering pattern inside by moving down one string you have resolved down the circle of fifths (by fourths).