An interval is an essential concept in music theory. It refers to the distance between two pitches, which can be measured in various ways, such as the number of steps or the frequency ratio.

Understanding intervals is crucial for musicians and composers, as they form the building blocks of melody, harmony, and chord progressions. In this article, we will explore what intervals are and how they work in music.

Types of Intervals

There are two types of intervals: melodic and harmonic. Melodic intervals refer to the distance between two successive pitches played one after another, while harmonic intervals refer to the distance between two pitches played simultaneously.

Melodic intervals can be further classified as either ascending or descending. An ascending interval moves from a lower pitch to a higher pitch, while a descending interval moves from a higher pitch to a lower pitch.

Measuring Intervals

Intervals can be measured using different systems, depending on the context.

In Western music theory, intervals are typically measured in half-steps or semitones. A half-step is the smallest distance between two adjacent notes on a piano keyboard or guitar fretboard.

For example, moving from C to C# is a half-step up. Two half-steps make up a whole-step or whole-tone.

Intervals can also be measured in terms of frequency ratios. For example, an octave has a frequency ratio of 2:1 because the higher note vibrates twice the frequency of the lower note.

Interval Quality

When naming intervals, we use terms like “major,” “minor,” “perfect,” “augmented,” and “diminished” to describe their quality or sound.

For example, a major third is made up of four half-steps (or two whole-steps) above the starting note. A minor third is one half-step (or one whole-tone) smaller than a major third. A perfect fifth is made up of seven half-steps (or three and a half whole-steps) above the starting note.

Augmented and diminished intervals are altered versions of major and minor intervals. An augmented interval is one half-step larger than a major or perfect interval, while a diminished interval is one half-step smaller.

Uses of Intervals

Intervals are essential to music theory because they form the basis of melody, harmony, and chord progressions.

Melodies are made up of a series of intervals that create a specific mood or feeling. For example, a major scale has a bright and uplifting sound because it contains several major intervals.

Harmonies are created by combining different intervals to create chords. For example, a major chord is made up of a root note, a major third, and a perfect fifth.

Chord progressions use different combinations of chords to create tension and release in music. For example, the “four-chord song” uses the same four chords (I-IV-V-vi) in different orders to create countless pop hits.


In conclusion, intervals are an essential concept in music theory that help musicians understand how melodies, harmonies, and chord progressions work. By understanding the distance between two pitches and how they sound together, musicians can create music that is both engaging and emotionally resonant. Whether you’re playing an instrument or composing your own music, understanding intervals is crucial for anyone who wants to excel in the world of music.