What are musical intervals? In music theory, an interval is a distance between any two musical sounds with regard to pitch. Knowing musical intervals is essential. It is the basis of all musical construction.
Moreover, intervals are examples of the simplest harmony used in music. It is also called two-part harmony.
We count the interval from the lower note to the upper, including both notes. In a diatonic scale, the smallest interval is a semitone (half step).
In this post, we are reviewing various kinds of intervals and how to construct them.
Table of Contents
Harmonic Interval and Melodic Interval
In terms of harmonic vs melodic intervals, they are two different concepts. Harmonic intervals sound together, while melodic intervals are sequential.
A harmonic interval is also known as a vertical interval. For example, when we play two tones simultaneously, we play a harmonic interval. The notes are written vertically on a clef.
A melodic interval is also a horizontal interval. We write the notes horizontally and play them one after another.
Intervals remain the same whether we use the treble clef or bass clef. For example, E to G is three intervals on both treble clef and bass clef.
Intervals in C Major
An Interval name is according to the number of letters included. For example, from C to E, it involves three letters: C > D > E; hence it is a third.
When two tones are the same without the pitch difference, we call it the Prime or Unison. Strictly speaking, it is not an interval.
Let’s use the C Major scale to show the names of intervals. The words below the notes indicate the kind of interval. As a convention, the interval names use ordinal numbers.
We call the Second, Third, Sixth, and Seventh Major intervals because they have a corresponding Minor Interval. For instance, the Major Second from C to D has a whole step (two half-steps). If we lower the D to D♭, from C to D♭ is one half-step, and we write C D♭. To avoid confusion, we do not recommend you to write C C♯, even though D♭ and C♯ are enharmonic tones, because this would not include two letters to be called a Second. Hence, C D♭ is the Minor Second.
The following are the corresponding minor intervals of the second, third, sixth, and seventh major intervals.
We call the Fourth and Fifth intervals the Perfect interval, not using major or minor. However, if we reduce a Perfect Fourth (or Fifth) by one half-step, we get the Diminished Fourth (or Fifth). On the other hand, if we increase a Perfect Fourth (or Fifth) by one half-step, we have an Augmented Fourth (or Fifth).
Abbreviated interval notations:
- P = Perfect
- M = Major
- m = minor
- d = diminished
- A = Augmented
- 1-7 = corresponding ordinal numbers
Most Common Augmented Intervals
Most Common Diminished Intervals
Intervals may be Inverted. This means that the tones change their relative positions. It is usually by moving one of the tones by an octave while the other remains at the same position. Inversion in an interval can happen with either the top or bottom tone.
The inversion of an interval changes the character of the interval, including the name and qualities.
Interval names change in inverted intervals.
All interval qualities are reversed except Perfect:
- Major becomes Minor
- Minor becomes Major
- Diminished becomes Augmented
- Augmented becomes Diminished
More examples of inversion –
Intervals in the D Major
The Major Scale furnishes us with a standard of measurement for all Intervals. We are able to apply the same rules to any major scale. Let’s use D Major for the exercise.
To Wrap Up…
In this post, we explained several things about musical intervals, a foundation for music construction.
- In major scales, we have Perfect and Major Intervals.
- If half a step expands a Perfect or Major interval, it becomes an Augmented interval.
- When the distance between two notes of a Major interval is lessened by one half-step, it is called a Minor Interval.
- If a Perfect interval is reduced by a half-step, it then becomes a Diminished Interval.
It may seem confusing in some ways; however, if you start with C Major and get well-versed in its various intervals, you will find it is easier to move to other scales. Keep practicing. Good luck!
Related: Music Fundamentals Series