• # Introduction To The Interval Cycle Of Fifths And Fourths

in Piano

Our focus in this lesson is on the interval cycle of fourths and fifths.

It’s very possible you’ve come across the term “circle of fifths and fourths” and are probably wondering if that’s what I intend to share on in this blog. Well the only way to find out is to keep reading.

For now, let’s start out by learning what an interval cycle is.

## “What Is An Interval Cycle?”

An interval cycle consists of a sequence of notes starting from a given note and ascending with a fixed interval between successive notes until the given note is reached.

For example, we can start from C:

…and ascend with a fixed interval (which could be a second, third, fourth, etc.) until C is reached.

So, the cycle starts and ends on the same note — just like the example I gave from C to C.

“So, Why Is It Called An Interval Cycle?”

It’s called an interval cycle because the distance between successive notes in the cycle is based on a fixed interval.

Today, we are looking at interval cycles of fifths and fourths and this implies that the distance between successive tones in the cycle are fifth and fourth intervals respectively.

Let’s take a closer look.

## Explained: The Interval Cycle Of Fifths

Before we go any further, let’s refresh our minds on the perfect fifth interval.

### A Short Note On The Perfect Fifth Interval

The perfect fifth interval is a product of the relationship between the first and fifth tones of the major scale. Using the C major scale (as a reference):

The first and fifth tones (which are C and G):

…when played together produces a perfect fifth interval.

“Check Out All The Perfect Fifth Intervals On The Keyboard…”

The C perfect fifth interval:

The Db perfect fifth interval:

The D perfect fifth interval:

The Eb perfect fifth interval:

The E perfect fifth interval:

The F perfect fifth interval:

The Gb perfect fifth interval:

The G perfect fifth interval:

The Ab perfect fifth interval:

The A perfect fifth interval:

The Bb perfect fifth interval:

The B perfect fifth interval:

Now we’ve refreshed our minds on the perfect fifth interval, let’s continue with the interval cycle of fifths.

### The Interval Cycle Of Fifths

The interval cycle of fifths consists of a sequence of notes based on perfect fifth intervals starting from a given note.

Starting from C:

…the interval cycle of fifths can be derived by ascending in perfect fifth intervals. Check out some of the perfect fifth intervals starting from C:

C to G:

G to D:

D to A:

A to E:

E to B:

B to F#:

…etc.

So, here’s a sequence of notes that belong to the interval cycle of fifths (as much as our virtual keyboard can take):

…however, here are all the notes in the interval cycle of fifths starting from C:

C   G   D   A   E   B   F#/Gb   Db   Ab   Eb   Bb   F   C

## Quick Insights On The Interval Cycle Of Fourths

It’s also important for us to discuss briefly on perfect fourth intervals before we proceed.

### A Short Note On The Perfect Fourth Interval

The perfect fourth interval is a product of the relationship between the first and fourth tones of the major scale.

In the C major scale:

…the first and fifth tones are C and F:

When played together, C and F produces a perfect fourth interval.

“Check Out All The Perfect Fourth Intervals On The Keyboard…”

The C perfect fourth interval:

The Db perfect fourth interval:

The D perfect fourth interval:

The Eb perfect fourth interval:

The E perfect fourth interval:

The F perfect fourth interval:

The Gb perfect fourth interval:

The G perfect fourth interval:

The Ab perfect fourth interval:

The A perfect fourth interval:

The Bb perfect fourth interval:

The B perfect fourth interval:

### The Interval Cycle Of Fourths

The interval cycle of fourths consists of a sequence of notes based on perfect fourth intervals starting from a given note.

Starting from C:

…the interval cycle of fourth can be derived by ascending in perfect fourth intervals. Check out some of the perfect fourth intervals starting from C:

C to F:

F to Bb:

Bb to Eb

Eb to Ab:

Ab to Db:

Db to Gb:

F# to B:

B to E:

E to A:

…etc.

So, here’s a sequence of notes that belong to the interval cycle of fourths (as much as our virtual keyboard can take):

…however, here are all the notes in the interval cycle of fourths starting from C:

C   F   Bb   Eb   Ab   Db   Gb/F#   B   E   A   D   G   C

## Final Words

From what we’ve covered in this lesson, you’ve clearly seen that indeed the following interval cycles exist:

The interval cycle of fifths

The interval cycle of fifths

If there’s a cycle of fifths and a cycle of fourths, why then do we say “circle of fifths” and “circle of fourths”?

I’ll tell you why this is so in a subsequent blog post. But for now, go ahead and master the interval cycles because they are the basis of cyclical chord progressions. Heck, the 2-5-1 chord progression is based on the interval cycle of fifths and fourths.

See you in the next lesson!

The following two tabs change content below.

#### Chuku Onyemachi

Head of Education at HearandPlay Music Group
Hello, I'm Chuku Onyemachi (aka - "Dr. Pokey") - a musicologist, pianist, author, clinician and Nigerian. Inspired by my role model Jermaine Griggs, I started teaching musicians in my neighborhood in April 2005. Today, I'm privileged to work as the head of education, music consultant, and chief content creator with HearandPlay Music Group sharing my wealth of knowledge with hundreds of thousands of musicians across the world.