What Are Harmonic Intervals in Music Theory?

In terms of music theory, an interval is defined as the difference between two pitches. There are many different kinds of intervals, such as horizontal, vertical, melodic, linear or harmonic. Let's focus on what a harmonic interval is.

Harmonic vs Melodic

Notes of a different pitch that are played simultaneously create harmony. The interval between these notes are called harmonic intervals. On the other hand, melodic intervals are when notes of different pitches are played in one after another, not together. Just like melodic intervals, there are harmonic 2nds, 3rds, 4ths, 5ths, 6ths, etc.

The harmony is a type of accompaniment. Take playing the piano as an example, the left-hand will usually play the harmonic intervals on the lower register while the right-hand typically plays the melody on the higher register.

Chords

Notes on a chord that are played together have harmonic intervals. The most common type of chords are major and minor chords. The triad is a type of major or minor chord that has 3 notes played either at the same time or one after another.

A major triad is played using the 1st (root) + 3rd + 5th notes of a major scale. A minor triad is played using the 1st (root) + 3rd + 5th notes of a minor scale.

Harmonic Hearing

Now that you know what a harmonic interval is on paper, try and hear it in practice. Establish a foundation in music theory and harmonic hearing with the following tips.

Play a harmonic interval, either on an instrument or as a recording. As you listen, see if you can hear the sound not as a blend, but as two individual notes being played together. As you are starting off, hold the harmonic interval for a longer note to give yourself time.

Then, sing the two notes out loud in succession. This useful method tests whether you are actually recognizing both notes or just their combination. Next, repeat this method using different instruments. Perhaps you'll find that it is easier for you to hear harmonic intervals with certain instruments.