Circle of 5ths

What is the circle of 5ths?

The circle of 5ths shows how closely different keys are related to each other. It is a particularly useful tool for modulation. The outer circle list the major keys. The inner circle list the relative minor keys. The treble staffs around the outside of the circle show how many sharps or flats define a key.

The most common uses cases for the circle of 5ths are –

1. Seeing which other keys along the circle are easiest to modulate to.
2. A quick reference for knowing which key a piece of music is in by looking at the number of sharps or flats.