If asked to play a scale you’re not familiar with, the first thing to do is pull up the circle of fifths to see the key signature.
In this article we’ll show you how to use this handy tool. You will also learn some theory that will help you better understand how the circle of fifth works.
First Things First: What is a Fifth?
In music theory a “perfect fifth” is the interval between the first and fifth note of a scale. Starting with a C, the perfect fifth is the G above it.
You can instantly recognize a perfect fifth by humming Twinkle Twinkle Little Star. Going from the first “twinkle twinkle” to the second “twinkle twinkle” is a perfect fifth.
As you might expect by the name, fifths are an important component of the circle of fifths.
Using the Circle of Fifths
This is the circle of fifths:
Image of circle of fifths showing major and minor keys provided by Just Plain Bill on Wikipedia via CC BY-SA 3.0
On the circle of fifths, major keys are shown on the outer circle and minor keys on the inner one. To the left of center are keys with flats and to the right keys with sharps.
At the top center of the circle of fifths is the key of C major, which does not have any sharps or flats. Moving to the right, you will find the key of G. This scale has one sharp, and as we said earlier is a perfect fifth above C.
As we continue to the right, each sequential key has an additional sharp and is a perfect fifth above the previous one. The next key, D, is a fifth above G and has two sharps. Another fifth takes us to A (three sharps), then E (four sharps), and so forth.
When moving to the left from C major, we first move a fifth down to F (one flat). Another fifth down takes us to B flat (two flats), and so on.
At the very bottom of the circle of fifths sharps and flats start to overlap each other. These key signatures can be written two different ways but are exactly the same: D flat major is the same as C sharp major, G flat major is the same as F sharp major, and B major is the same as C flat major.
The circle of fifths also shows major and minor keys that share a key signature. For example, G major and E minor both have one sharp. The minor keys in the inner circle work exactly the same way as their major counterparts – as you go around they’re separated by fifths.
The next time you need to play a scale you’re not familiar with, simply pull up the circle of fifths to find the key signature. Easy as can be!