Ah the circle of Life.  As corny as this sounds, there are also circles in Western music composition.  The circle of 5th and related 4ths is a great way to find chord substitutions to work in composing, decoding, and soloing over almost any Western song in any key.

Prerequisites to this section [you must know]

Chord Names with Numbers | Counting Keys |  Scales and Modes | Chord Progressions

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Circle of 5ths (and 4ths)

The circle of 5ths (and 4ths) is essentially a wheel of how Western musical chords relate to similar sounding chords which can be substituted into a chord progression to give the song more variety, colour, and expression.  It is also a handy way to find the key of a song and the standard chord progressions (especially the 1, 4, 5 m6) in that key

Rules

• All letters represent chords
• The chord letter you start on is the key of the song (not the tonic – tonal centre)
• The outer wheel of the circle is the major scale
• The inner wheel of the circle is the minor scale
• The intervals between chords are in whole tones and do not include semitones (sharps and flats) in the counting of the intervals
• If you go right on the circle your chords change by an interval of 5 whole tones on a scale
• If you go left from the starting chord the chords change by an interval of 4 whole tones on an octave whole tone  scale

Important theory notes:

• In naming – a flat chord is the same as the sharp chord the letter  below it                ex Db = C#; F#m = Gbm
• There are no flat or sharps between B and C or E and F (this is why the circle works); so no such chords as B#, Cb, E#, Fb – not in this universe! – so those fictional chords are not on the wheel
• For convenience in folk, rock, and blues we to use these chord names:
  • sharps – C# F#, G# (C#m, F#m, G#m) – not generally using Db, Gb, Ab
  • flats – Bb, Eb  (Bbm, Ebm) – not generally using A#, A#m, D#, D#m

Why?….

Optional theory notes in chord  naming: [skip this part if it confuses you]

• The wheel above uses all the names jazz and classical players would
• the use of a flat name or sharp name corresponds to the musical style ex. a song in C# to a rock player would be a song in the key of Db to a jazz player; also in the Key of E, a rock player would call the chord a C#m not a Dbm even though its the same chord; but a jazz or classically trained person could use either name – though usually if the key is flat, all chord names would be flat and not sharp; if the key is sharp, all half-tone chord intervals would be called sharp

Circle of 5ths / 4ths for folk, rock, blues, (newbie jazz) players

So folk, rock, and blue guitarists would probably be better off using the circle of 5ths . 4ths in this format. Jazz, funk, fusion, and pop music players would have to make note of the common alternative flat/sharp names written in smaller font in some places on the wheel

Standard Uses

Finding the standard chord progressions

Start with the Key Chord on the outside wheel

1. the chord to the immediate right is the Vth (dominant chord)
2. The chord to the immediate left is the IVth (subdominant chord)
3. The chord directly inside [on the inner wheel] is the relative minor 6th chord (vii-m)
4. The chord directly inside inner wheel of the Vth is the minor 3rd (iii-m) of the key
5. The chord directly inside of the IVth is the minor 2nd (ii-m)

So let’s look at the Key of C and apply the rules:

1. G is the Vth (dominant) chord in the key of C
2. F is the IV (subdominant) chord in that key – often IV is maj7 – ec. Fmaj7
3. Am is the vii or VIIm (relative minor) chord
4. Em is the iii or IIIm (minor 3rd or phrygian minor)
5. Dm or Dm7 is the ii or IIm (minor 2nd dorian minor)

The most common songs in folk, rock, or blues would then use these chords:

• C, F, G, Am and occasionally the minor third Em –  I, IV, V, vii,  iii ; jazz players would often use the minor second – Dm

Try this for the key of A

• You should have A (I), Bm(ii), C#m (iii), D (IV), E(IV), F#m (vi), G#07 (dim vii)
• The most common chords in a folk, rock or blues song in the key of A would be:
• A, D, E, F#m and occasionally the minor third C#m – in jazz you would often have the minor 2nd Bm

*remember this is  whole tone step so the space between B and C# is  whole tone. C would not be correct as it is only the half tone up from B – there are no sharps and flats between the two

Let’s try the key of Bb, we would get:

• Bb (I), *Cm (ii), Dm (ii) Eb (IV), *F (V), Gm (vii), A07 (dim-7)
• *again because of whole tone relations
• The most common chords in a folk, rock or blues song in the key of Bb would be:
• Bb, Eb, F, Gm, Dm –  I, IV, V, VIm, IIIm – jazz players would often use the IIm – Cm

Transposing Songs

The circle of 4ths/5ths is very useful for transposing songs.  You just need to move the tonic (I) and its surrounding chords around the wheel.

In the diagram the group around the Tonic (I) in the key of C is in yellow.

C, F, G, Am, Dm, Em. =. I, IV, V, vi, ii, iii

Imagine A is now the tonic, you would get:

A, D, E, F#m, Bm, C#m – I, IV, V, vi, ii, iii – key of A

Modulating to New Keys with the Circle

What you can do here is look to the chord on the right of the tonic chord (I) and then make the new tonic.  IN this case we would introduce the D chord that is to the right of the G.  What this does is change the tonic centre to G instead of C.  Since G is within the key of C though, this becomes a smooth and logical change – either for a single chord or to a new key in the song.

Try this progression

C, D, F, G  –  sounds like a few tunes you heard before? Go to SearchbyChords.com and you will find dozens by name alphabet and chord progression. [you have to search through to find songs with all these chords – some have more or less]

How about this?  C Bb F. G. (I, VII, IV, V)- this time we went left to the 4th. Try playing these notes in different orders.

Circle Substitutions – relative Key modulation

You can use chords beside and above/ and below each other on the wheel as you move from tonal centre to tonal center to create interesting chord progressions based on these substitution.

Try this chord progression:

C,  G, D,  Em, F, Am,  G

The basic key is C, F, and G with Am as the relative.  I substituted the G with an Em and I replaced what could work as a C with an Am

Most of these common rock progressions came about by knowledge that is based on the circle of fifths and the use of relative key modulation.

• Don’t Stop Believing Progression, I – V – vi – IV (G – D – Em – C)
• the 50’s Progression, I – vi – IV – V (G – Em – C – D).
• the Canon, I – V – vi – iii – IV – I – IV – V (G – D – Em – Bm – C – G – C – D)
• the Blues Progression, I – IV  – I –V –IV –  I  (G – C– G  – D –C –  G ).
• Smoke on the Water Progression, ii – IV – V (am – C – D)
• the Good Love Progression, I – IV – V – IV (G – C – D – C).
• Descending Flamenco Progression  vi – V – IV – III (em – D – C – B (not Bm!)
• As My Guitar Gently Weeps Progression ii – I – V/vii – bVII (- VI) (am – G – D/f# – F (- E)

If you take a look at autochords.com you can see how the common relative substitutions work.  (You can also find some weird chord progressions)

Finding the key from notation key signature

This tool is handy when working with folks who use standard music notation instead of / or in addition to tabulature

Here is a standard notation music score.  This key has 4 sharps. What key is it in?

So for the example above – with four sharps– you would count right on the outer wheel, starting at the C chord (always) which counts as zero (not 1) four spaces to the right

The key is E – using the method for finding chords, the chords in the key are:

E (key), F#m7 (ii), G#m (iii), A (IV), B (V), *C#m (vi), D#o7(vii-dim)

SO you can generally count on the folk, rock, or blues song having the chords in bold in the progression 0f that tune.  

Important Caveat and Heads Up:

Sometimes “lazy” music publishers reassign the key signature so that it has the fewest accidentals (sharps and flats) so that the key signature is not as technically correct as it should be.  More uncommon, but even more annoying is that some amateur composers and publishers publish the standard music according to a song’s Tonal centre (tonic) instead of its actual key.  Remember the discussion from Tonic chord progression numbers?  Remember the case of

Desi Serna has an important discussion of this issue in detail in Fretboard Theory II