The Intervals

The performance of any piece of music (except, perhaps, 4’33” John Cage) involves the sequential reproduction of sounds. One of the parameters by which sounds differ from each other is their pitch.

The relationship between two musical sounds in terms of their pitch (or the “distance” between sounds in terms of their pitch) is called an interval.

Thus, any melody, any musical text, is a sequence of sounds following each other at certain intervals.

The distance between sounds can be measured either in semitones and whole tones, or in scale steps. The distance in scale steps determines the name of the interval. Sometimes the term "width" is used instead of the "distance".

Let's look at the classification of musical intervals and their names.

Classification of intervals

Harmonic and melodic intervals

The bottom sound of an interval is called the base, the top sound is called the top.

The sounds of the interval taken sequentially from the base to the top form an ascending melodic interval; from top to bottom — descending melodic interval.

The sounds of an interval taken simultaneously form a harmonic interval.

Melodic intervals are also called horizontal,

and harmonic intervals are called vertical.

Simple and compound intervals

Intervals vary in width, determined by the number of scale steps they cover. Intervals formed within an octave are called simple. Intervals wider than an octave are called compound intervals.

Compound intervals inherit the properties of simple ones (for example, ninths, like seconds, can be major or minor). Intervals wider than a double octave (quint decimals) are traditionally not considered in music theory.

The qualities of the intervals

There are perfect (p), minor (m.), major (M.), augmented (aug.), diminished (dim.), intervals.

• The terms “major” and “minor” refer to the intervals of second, third, sixth and seventh..

• The term “perfect” refers to the intervals of first, fourth, fifth and eighth.

The augmented and diminished intervals

In music theory, the terms “diminished” and “augmented” intervals imply a change in the number of tones in the interval, while the number of steps remains the same.

• Augmented — the interval (perfect or major) is increased by a half tone.

• Diminished — the interval (perfect, except the first, or minor) increased by a half tone.

List of musical intervals

Simple Intervals

The Name	Scale steps	Tones	Quality	Designation
First (prima)	1	0	perfect	p1
Second	2	0,5 (half tone) 1 (whole tone)	minor major	m2 M2
Third (tertia)	3	1,5 2	minor major	m3 M3
Fourth (quarta)	4	2,5 3	perfect augmented	p4 aug4
Fifth (quinta)	5	3 3,5	diminished perfect	dim5 p5
Sixth (sexta)	6	4 4,5	minor major	m6 M6
Seventh (septima)	7	5 5,5	minor major	m7 M7
Eighth (octave)	8	6	perfect	p8