How to Change Key Signatures Using the Circle of Fifths

Designed as a teaching aid for musical theory, the circle of fifths neatly organizes the twelve basic musical keys into a wheel. Students can make their way around the circle of fifths wheel, learning the relationships between each of the different keys. Moving around the circle of fifths chart also makes it easy to understand how to change key signatures because of the clear arrangement of sharps and flats in the circle.

Instructions

Difficulty: Moderate

1. Notice the relationship of the keys to one another on the circle of fifths. If you start at one key on the circle and move clockwise, the next key you hit is five whole tones about the previous one. When you start at C, for example, the next key you hit will be G, and the one after that is D.
2. Figure out how many sharps or flats each key has. The circle of fifths often has numbers printed on its inside, and these indicate the number of sharps or flats in each key signature. If you start at C and move clockwise, the number of sharps in a key signature increases by one with each step. If you start at C and move counter-clockwise, the number of flats increases by one with each step. The F-sharp at the bottom of the circle has 6 sharps and 5 flats.
3. Use the circle of fifths to discover not only how many sharps or flats there are in a key signature but what these sharps or flats actually are. The first sharp is always F, and you can move around the circle clockwise, starting from F, to learn which other sharps there are in a particular key signature. The first flat is B, and you can move around the circle counter-clockwise, starting from B, to learn which other flats there are in a key signature.
4. Understand that you can rotate the letters on the circle three steps counter-clockwise to find the key signatures of minor scales. The numbers on the inside of the circle remain in the same position after the rotation, and, as with the major keys, these numbers indicate the key signatures of minor scales. This shift from major to minor shows the relationship between relative majors and minors.
5. Learn how to change from one key to another consonant key. A chord in one key will sound consonant (or very melodic) when paired with a chord from a neighboring key (one counter-clockwise or one clockwise step away). Two keys are more consonant the closer they are together.
6. Practice changing key signatures, or modulating the key, within one single piece of music. Notice which key signatures sound best with one another.

Tips & Warnings

• Key signatures are closely related to one another when they have the same number of sharps and flats.
• Two keys are most dissonant when they are 6 steps apart from one another.