We've heard about it. We have probably seen the slightly intimidating diagram. But what actually is a circle of fifths – and why is it useful to know about in music theory?
What is a circle of fifths?
The circle of fifths is a musical pattern in which the 12 chromatic pitches of the scale are presented in a sequence of perfect fifths. If you were to start a sequence with C, it would then move to the chord a fifth above – in this instance, G. It would then continue on to D, A, E and B etc.
What are its origins?
Many believe that Pythagoras came up with the concept of a circle of fifths in the sixth century BC, although there is little evidence to suggest this. During the late 1670s, a Ukrainian composer and theorist called Nikolay Diletsky wrote a treatise about composition titled Grammatika. Its purpose was to act as a guide for composition using music theory principles. By 1728, Johann David Heinichen had updated its format into the version we know today.
What does the circle of fifths show?
The circle of fifths can be thought as a colour wheel, each keys relationship with one another is carefully displayed on the circle. On a colour wheel you have primary, secondary and complimentary colours placed next to each other, this is the same with keys and their relation to others. The closer they are situated on the circle, the closer together they sound.
As you work your way clockwise around the circle, starting from the top at C major, you keep adding one sharp until you reach the southern hemisphere where you arrive at C# major, with a daunting seven sharps! If you were to go round anti-clockwise you will pass through all the keys that have flats, starting with F major.
Why is it called a circle of fifths?
This visual representation of all 12 keys in Western music displays each key five steps apart, hence the circle of fifths. Starting from the top you have C major, by moving five steps forward (C, D, E, F and G) you reach the key of G major. This pattern is repeated the entire way around the circle until you arrive where you started at C again. If you were to move around the circle anti-clockwise, you’ll find yourself moving in fourths, however this is rarely acknowledged.
What do the small letters inside the device mean?
The capital letters on the outside of the circle refer to all the major key centres, these are the keys that sound ‘happy’. The lowercase letters on the inside represent the minor key centres, these are the keys that often sound ‘sad’. These are, again, deliberately presented in a certain order on the circle. Each minor key shares the same key signature as a major key (how many sharps or flats it has) and therefore can be placed with their relative major key on the circle.
How is the circle of fifths used in music?
Ever since the Baroque era, the circle of fifths has been used in compositions from most Western genres of music; classical, folk, jazz, and pop. When songs or works modulate key for harmonic interest, they mostly move around the circle of fifths according to their placement on the circle. The B section in George Gershwin’s ‘I Got Rhythm’ utilises the circle of fifths as it moves around four key centres through an eight-bar structure.
Purcell (Rondeau from Abdelazer), Albinoni (Sonata op. 3 - Allegro), JS Bach (Toccata and Fugue in D minor), Vivaldi (many, including the Violin Concerto in D minor Op.3-11 - Allegro), Handel (Concerto Grosso in D and Messiah Overture) are among the composers to employ the device.
Visit our musical terms dictionary to find out about other musical definitions you may not know.