# Cycle of fifths theory

## How it works

Knowing the intense hatred most people have for music theory, I'm going to keep this very simple.

If you have any questions on music theory, I'll try to answer them through the comments box below.

Starting with the key of C at the top of the circle - C has no flats or sharps.Visually on the piano keyboard, there are no black notes used, and the key signature sign shows no flats or sharps.

Every step in the clockwise direction adds a sharp to the key signature (the squiggly bit at the start of music scores) and also to the major scale. So G has one sharp, and goes

G A B C D E F♯ G (the sharp sign is like a hash key)

then D goes: D E F♯G A B C♯ D - and so on. (two sharps)

## Flat keys

If you read the cycle anti-clockwise, the interval is a fourth (C,D,E,F)

Now we're going anti-clockwise, adding a flat each step.The flat sign is like b. The first key is F, with one flat. The notes of an F major scale are: F G A Bb C D E F.

Next is Bb, with 2 flats, and so on.

Eb is a very important key, as so many jazz standards are written in this key. Ab is very uncommon by comparison.

My advice would be: learn the sharp keys clockwise.

C G D A E (also the chords to Hey Joe by Hendrix which is a neat way of remembering the sequence.)

Then learn the flat keys up to Ab. The bottom few keys on the diagram are very infrequently used, as they are such a pain to read.

## Practical uses

First, we can identify the key of any written music score. The ii V I chord progression and the V I progression are the two most prevalent chord changes in music. Just by using adjacent steps we can work these out for any key. The ii is always minor, the V is always a 7th, the one is always major.

In D: Em A7 D (shown on the diagram)

In C: Dm G7 C

The V - I would be G7 to C, E7 to A, C7 to F, etc.

Another common progression, especially in jazz standards, is the minor ii V I.

In this type of chord sequence, the first chord is m7b5, second chord is 7th, last chord is minor.

Using C minor as an example, you would have Dm7b5, G7, Cm. Blue Bossa is one standard that uses this sequence. Dance me to the End of Love by Leonard Cohen is another.

Most jazz tunes are a series of ii V I or minor ii V I chords.

## Great application

Another way to use this cycle: From any point, the notes on either side give you the I,IV,V chords in any key. For instance, A has D and E adjacent to it - the three major chords in that key.

To play a blues in A, just use A7, D7, and E7. So we have just added a 7th to the three chords to make it blues stylee.

Relative minors - to find the relative minor of any chord, just go round the cycle, three steps.

• From C, three steps is A - so the relative minor chord is Am
• From G, round three steps is E, so the relative minor chord is Em
• As the relative minor pentatonic scale always works for improvising, this can be very useful. In the key of C, use Am pentatonic, in the key of G use Em pentatonic, and so on.

## Songwriters

All this material should be invaluable to songwriters. In fact, putting it into practice will really help you understand the mechanics of harmony and music.

Try playing the progression Am D7 G maj7 Cmaj7 - used in countless songs, but Autumn Leaves and I Will Survive (with Dm replacing D7) are good examples. Perfect Day is another(Lou Reed), and The Beatles You Never Give Me Your Money from the Abbey Road album. Then Fly Me to The Moon is the same, but using Dm as the second chord.

## Intervals on the piano keyboard

My new hub guitar and piano - easy theory might help if you are new to music theory. I find a little goes a long way - maybe combine 20 mins a day actual practice with 10 mins theory and your musical development might really take off.

The cycle of fifths is also the cycle of fourths , depending whether you are going clockwise or anti - clockwise.

## More by this Author

Paraglider 7 years ago from Kyle, Scotland

Hi Jon - It's good to spread the word, but I can't help feeling that if you don't complete the cycle to show the enharmonic change from F# to Gb (at six o'clock), folk won't see why it is a true cycle, (thanks to the great invention of equal temperament).

Jon Green 7 years ago from Frome, Somerset, UK Author

Hi Paraglider - fair point. I've amended the diagram.

Cheers, Jon