Cycle of Fifths
In most styles of music, it is of critical importance that you understand the Cycle of Fifths. The Cycle of Fifths is a graphical representation of all the key centres in Western music, how they relate to each other and what notes are in their key signature. Let's have a look at the one below.
The first thing to note is the Cycle starts at C major, at the very top of the circle. It starts here as C major has no sharps or flats in the key signature. If you move clockwise around the circle, each time the root note is raised by a perfect fifth and a sharp is added to the key signature. If you move counter clockwise, the root note falls by a fifth and adds one flat. Around the inside of the circle are the relative minors - these are the minor scales that have the same key signature as the corresponding major key. By using the circle, we can see for example that the relative minor of D major is B minor, and that both these key centres have a signature that contains F# and C#.
There are several reasons that the Cycle of Fifths is so important in jazz:
You may also hear the Cycle of Fifths referred to as the Circle of Fifths, the Cycle of Fourths or just the Circle. It is sometimes called the the Cycle of Fourths because if you move counter-clockwise the root notes raise by a perfect fourth. This is the same as falling a fifth.
Note that it doesn't matter what way you move around the circle, or even which side you write the flats and sharps on. In jazz it is generally more beneficial to think of the Cycle as moving through the flats first as this is the order most chord progressions use.
Hear the root notes of the cyclic movement below:
Order of notes - C F Bb Eb Ab C# F# B E A D G (C)
There are several reasons that the Cycle of Fifths is so important in jazz:
- The strongest resolution in music is that of the falling fifth, say for instance when the chord root moves from G to C. (This is for multiple reasons that will be discussed further in the Advanced Jazz Theory topics - for now just accept it)
- As jazz moves through so many different keys, it is important that you know the key signatures of all the keys.
- The key centres to the left and right of the one you are looking at are the most closely related keys. It is likely that the music will move between these keys and also the relative minor.
- For the reason stated above, many common chord progressions follow the movement of the Cycle. This includes the basis of most jazz music - the II V turnaround (see Beginner Jazz Theory --> II V Progression).
You may also hear the Cycle of Fifths referred to as the Circle of Fifths, the Cycle of Fourths or just the Circle. It is sometimes called the the Cycle of Fourths because if you move counter-clockwise the root notes raise by a perfect fourth. This is the same as falling a fifth.
Note that it doesn't matter what way you move around the circle, or even which side you write the flats and sharps on. In jazz it is generally more beneficial to think of the Cycle as moving through the flats first as this is the order most chord progressions use.
Hear the root notes of the cyclic movement below:
Order of notes - C F Bb Eb Ab C# F# B E A D G (C)