In this lesson, you will learn about the circle of fifths, which will help you to remember the keys and will provide insight into numerous relationships in music.
The circle of fifths looks like a clock, with “C” being at the top, in the 12:00 position. The key of C major has no sharps or flats. Going clockwise, the key that is a fifth up from C (G) has one sharp. The next key, which is a fifth up from G, is the key of D, and has two sharps. A fifth up from D is A, and it has three sharps. Continuing around the circle, you will find that each time you go up a fifth, you arrive at a key that has one sharp more than the previous key.
Take some time to begin learning the key signatures. The easiest approach is to start at the top of the circle and go clockwise, starting with the key of C and memorizing the first three sharp keys. Then, beginning again at the top of the circle, go counter-clockwise, so that you will be learning the first four flat keys. Once you have done that, you will only have four keys at the bottom of the circle to learn.
When you are familiar with the circle, you can begin using it to find common chord progressions. The chords in the I – IV – V progression are all adjacent on the circle, with the I chord being in the middle. If you choose any note on the circle and call it I, you will see that IV is to the immediate left, or one key over in the counter-clockwise direction, and V is to the immediate right, or one key over, clockwise. For example, the C chord is the I chord in the key of C. F (one key to the left of C) is the IV chord in the same key and G (to the right of C) is the V chord. Using this method, you can easily determine the I – IV -V progression in all 12 keys. Be sure to practice playing them!
Now look at the iii – vi – ii – V – I progression. This chord progression in the key of C is Em (iii), Am (vi), Dm (ii), G (V), C (I). This entire progression is laid out in order on the circle, moving counter-clockwise. For example, in the key of C you start with E and continue to A, D, G and C. Just remember that the iii, vi and ii chords are minor, as indicated by the lower case Roman numerals.
By investing just a small amount of time to learn and play with these chord progressions (preferably in all of the keys), you will find that you are able to learn songs much more quickly and will even be able to predict the chords in songs that you haven’t yet played!