Rotation in music theory is a technique used to generate new chords and harmonies from an existing chord progression. It involves moving the notes of a chord up or down by a certain interval, creating new chord voicings that are related to the original.

Understanding Chord Progressions:

Before we delve deeper into rotation, let’s have a quick overview of chord progressions. In music theory, a chord progression is a series of chords played in sequence. It is the backbone of most songs and provides the harmonic structure for the melody and lyrics.

Example:

Consider the following chord progression in C major: C – Am – F – G

This sequence of chords forms the basis for many popular songs such as “Let it Be” by The Beatles.

What is Rotation?

Rotation is a technique where we take an existing chord progression and move each chord up or down by a certain interval. This creates new harmonies that are related to the original chords.

Example:

Let’s take our previous example of C major – Am – F – G and rotate it by moving each chord up one step:

As you can see, we get a completely new set of chords while still maintaining some similarity with the original progression.

Types of Rotation:

There are two types of rotation: clockwise and counterclockwise.

Clockwise rotation involves moving each note of a chord up by one scale degree. For example, in C major, rotating clockwise would move the C major chord to D minor, E minor, F major, and so on.

Counterclockwise rotation involves moving each note of a chord down by one scale degree. For example, in C major, rotating counterclockwise would move the C major chord to B flat major, A minor, G minor, and so on.

How to Use Rotation:

Rotation is a great technique to use when you want to add variety to a chord progression or create a new section in a song. It’s important to note that not all rotations will work harmonically, so it’s important to use your ear and experiment with different rotations until you find something that works.

Let’s say we want to create a new section for our previous example of C major – Am – F – G. We can use rotation to generate new chords that are still related to the original progression:

This new progression maintains the same harmonic structure as the original but adds some variety and interest.

Conclusion:

Rotation is a versatile technique that can help you generate new chords and harmonies from an existing progression. By moving each note of a chord up or down by a certain interval, you can create new voicings that are related to the original. Remember to use your ear and experiment with different rotations until you find something that works harmonically.