Intervals on the Fretboard

Introduction

In our previous lesson, Interval Basics, we learned how intervals describe the distance between two notes and how they're named.

Now we're going to put that knowledge into practice on the guitar.

Rather than calculating semitones or counting note letters, we'll begin recognising intervals by the positions of our fingers on the fretboard.

We'll focus on three common intervals: the perfect 5th, major 3rd and minor 3rd.

By exploring these relationships, you'll learn to recognise their shapes, understand where they're used in music and see how the same interval can be played in different positions on the neck.

Understanding Interval Shapes

On the guitar, an interval can be represented by the positions of two notes on the fretboard.

The first note is our root note, which we'll use as the starting point for measuring the interval. The second note determines the interval's distance from that root.

When we play these notes on neighbouring strings, they form a recognisable shape.

One of the useful things about guitar tuning is that many of these shapes can be moved around the fretboard without changing the interval itself.

For example, if we move both notes of a perfect 5th up two frets, we'll still have a perfect 5th. The pitches have changed, but the relationship between them remains the same.

Perfect 5ths

What is a Perfect 5th?

A perfect 5th is an interval spanning five note letters and seven semitones.

For example, the interval from G to D is a perfect 5th.

Counting the note letters gives us:

That's five note letters, giving us the interval number of a 5th.

The distance between G and D is seven semitones, making it a perfect 5th.

Finding a Perfect 5th on the Guitar

Let's start with G on the 3rd fret of the low E string.

To find a perfect 5th above G, move to the A string and play the 5th fret.

This gives us:

• G — Low E string, 3rd fret
• D — A string, 5th fret

These two notes form a perfect 5th.

Notice that a root note's perfect 5th is two frets higher on the next higher-pitched string, except when crossing from the G string to the B string.

This creates one of the most recognisable interval shapes on the guitar.

Try playing the notes separately, then together, and listen to how they sound.

Perfect 5ths and Power Chords

You may already be familiar with this shape, even if you didn't know its interval name.

It's the foundation of a power chord, one of the most commonly used chord shapes in rock, punk and metal.

A basic power chord consists of a root note and its perfect 5th.

Unlike major and minor chords, power chords contain no 3rd. This means they don't have a major or minor quality.

You might also have seen power chords played using three notes. In this case, the third note is usually another G, one octave above the original root.

The essential relationship remains the same: root + perfect 5th.

Understanding Guitar Tuning

In standard tuning, the six guitar strings are tuned E – A – D – G – B – E, from lowest to highest.

Most adjacent strings are separated by a perfect 4th (5 semitones). The exception is the G and B strings, which are separated by a major 3rd (4 semitones).

Why does this matter?

Because the tuning intervals are consistent, the relationships between notes remain the same across most adjacent string pairs.

This means that interval shapes can be moved between string pairs without changing the distance between the notes.

There is one important exception: when a shape crosses the G and B strings, it needs to be adjusted by one fret to maintain the same interval.

Learn any interval relationship once, and you can apply it across the fretboard.

Exploring Other Intervals

The same principle applies to other intervals across the fretboard.

Take a minor 3rd, for example. A minor 3rd is a distance of 3 semitones between two notes.

Just like the perfect 5th, a minor 3rd has a consistent shape that can be moved around the fretboard.

Because most adjacent guitar strings are tuned a perfect 4th apart, the shape stays the same across those string pairs.

The only exception is between the G and B strings, where the shape must shift by one fret to maintain the same interval.

Minor Thirds

A minor 3rd is the distance of 3 semitones between two notes.

On the fretboard, we can find a minor 3rd by starting from the root note (R), moving to the next higher string and back 2 frets.

For example, starting on A at the 5th fret of the low E string, moving to the A string and back to the 3rd fret gives us C, the minor 3rd.

This shape stays consistent across most adjacent string pairs. However, when moving from the G string to the B string, we only move back 1 fret because of the difference in tuning.

The notes change as we move around the fretboard, but the interval between them always remains the same.

The Same Rules Apply

Just like the perfect 5th, the minor 3rd follows a consistent shape across most adjacent string pairs.

Because the G and B strings are tuned a major 3rd apart rather than a perfect 4th, we need to adjust the shape by one fret when moving between them.

The same principle applies to any interval we want to find on the fretboard.

Major Thirds

A major 3rd is the distance of 4 semitones between two notes.

On the fretboard, we can find a major 3rd by starting from the root note (R), moving to the next higher string and back 1 fret.

For example, starting on A at the 5th fret of the low E string, moving to the A string and back to the 4th fret gives us C♯, the major 3rd.

This shape stays consistent across most adjacent string pairs. However, when moving from the G string to the B string, we stay on the same fret because of the difference in tuning.

The notes change as we move around the fretboard, but the interval between them always remains the same.

Applying the Same Principle

As with the previous two examples, the major 3rd follows a consistent shape across adjacent string pairs, requiring a one-fret adjustment when moving between the G and B strings.