8.21 Applying the circle of fifths

In Chapter 8.20 The circle of fifths you’ve learned what the circle of fifths is. In this chapter, you will learn how to apply the circle of fifths.

1. What can you do with the circle of fifths?

Using the circle of fifths, you can:

Five examples of these methods:

The half of the circle of fifths with sharps gives us the scale of E major: C (0) - G (1#) - D (2#) - A (3#) - E (4#).

The half of the circle of fifths with flats gives us the scale of E flat major: C (0) - F (1b) - Bb (2b) - Eb (3b).

The half of the circle of fifths with flats gives us the scale of B flat major: C (0) - F (1b) - Bb (2b).

A minor third below Bb is G: the G minor scale has two flats.

The half of the circle of fifths with sharps gives us three sharps: C (0) - G (1#) - D (2#) - A (3#).

The half of the circle of fifths with flats gives us one flat: C (0) - F (1b).

We can recognize the key of a piece of music by two steps:

counting the number of accidentals in the scale.
looking at the last measure and its final pitches or chord to determine the tonic, which is the tone of the key.

The tonic of the final chord is also the tonic of the scale in which the piece was written, the final chord is almost always the first degree.

The bass tone, or lowest tone of the final chord is almost always the tonic.

Look closely to find the final measure, this is not always the last notated measure (for example, when a piece ends with D.C. al Fine).