# 6.8 Augmented fourth, diminished and augmented fifth

 Category: Harmony | Tags: Intervals, Ear training: intervals

### Theory

In Chapter 3.6 Perfect fifth you’ve learned what a perfect fifth is and in Chapter 4.8 Perfect fourth and octave what a perfect fourth is. In this chapter, you will learn about the augmented fourth, diminished and augmented fifth. In the videos and examples I show how to make augmented fourths, diminished and augmented fifths. You learn to recognize augmented fourths, diminished and augmented fifths and you are goning to make them yourself in the exercises. You will also learn to distinguish perfect and augmented fourths and perfect fifths by ear.

## 1. Augmented fourth

The fourth from F to B is called an augmented fourth and is made up of six half steps (three whole steps).

An augmented fourth is made by raising the highest tone of a perfect fourth, or by lowering the lowest tone of a perfect fourth.

The augmented fourth F B.

### Examples

How do you raise a perfect fourth?

The augmented fourth is a somewhat odd interval. This can occur in different forms. From beautiful to "devilish", or false. There is a story that a certain type of fourth was banned in the Middle Ages, being associated with the devil. However, there is no evidence for this story. This type of fourth is the only interval that has its own name: the tritone. In etude no. 3 by Chopin, you can hear a lot of tritones:

### Examples

Which tones do you get if you make augmented fourths on the natural notes?

## 2. Diminished fifth

The fifth from B to F is called a diminished fifth and is made up of six half steps (three whole steps).

A diminished fifth is made by lowering the highest tone of a perfect fifth, or by raising the lowest tone of a perfect fifth.

The diminished fifth B F sounds the same as an augmented fourth.

### Examples

How do you lower a perfect fifth?

### Examples

Which tones do you get if you make diminished fifths on the natural notes?

## 3. Augmented fifth

The fifth from C to G# is called an augmented fifth and is made up of eight half steps (four whole steps).

An augmented fifth is made by raising the highest tone of a perfect fifth, or by lowering the lowest tone of a perfect fifth.

The augmented fifth C G# sounds the same as a minor sixth.

### Examples

How do you raise a perfect fifth?

The augmented fifth is found in the harmonic and melodic minor scale.

### Examples

Which tones do you get if you make augmented fifths on the natural notes?

## 4. Inversion of an augmented fourth

By inverting the augmented fourth F B we get B F, this is a diminished fifth.
The inversion of an augmented fourth is a diminished fifth.

## 5. Practise

Harmony exercise 6a: practise recognizing perfect, diminished and augmented fourth and fifth from musical notation.

Harmony exercise 6b: practise making perfect, diminished and augmented fourth and fifth on the natural notes.

Harmony exercise 6c: practise making perfect, diminished and augmented fourth and fifth on all notes.

## 6. Ear training

### Practise

Ear Training exercise 6f: practise distinguishing the difference between perfect and augmented fourths and perfect fifths by ear.

### Example question

Which interval do you hear?

Choise 1: perfect fourth

Choise 2: augmented fourth

Choise 3: perfect fifth

### Practical steps

Sing the interval being played to train your inner hearing abilties. Decide which interval is being played.