Introduction to Intervals

An interval is the distance between two notes.

Intervals have two main categories: melodic (successive pitches) and harmonic (simultaneous pitches).

Melodic and harmonic intervals can be labeled two ways: distance (unison, 2^nd, 3^rd, 4^th, 5^th, 6^th, 7^th, octave, etc.) and quality (major, minor, augmented, diminished).

Look at the picture below to see an example of melodic intervals. In a melodic interval, the two notes take turns. The U stands for unison, which means the same note is played twice.

Look at the picture below to see an example of harmonic intervals. In a harmonic interval, the two notes are played at the same time.

To identify the distance portion of an interval, count the number of notes between the two pitches, including the two pitches on the staff. For example, the picture on the right shows the distance of several intervals in brackets. For the ascending B to D, it is a 3rd because you would count B as 1, C as 2, and D as 3. For the ascending G to D, it is a 5th because you would count G as 1, A as 2, B as 3, C as 4, and D as 5.

For the descending D to E, it is a 7th because you would count E as 1, F# as 2, G as 3, A as 4, B as 5, C as 6, and D as 7. For the descending D to D, it is an 8th because you would count D as 1, E as 2, F# as 3, G as 4, A as 5, B as 6, C as 7, and D as 8. We can also refer to this as an octave.

It is important to memorize what each interval distance looks like so you can identify them quickly when sight reading.​

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3rds, 5ths, and 7ths always have both pitches on lines or spaces. 3rds are located on adjacent lines or adjacent spaces. 5ths skip a line or space between notes. 7ths skip two lines or spaces between notes.

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2nds, 4ths, 6ths, and octaves always have one pitch on a line and one on a space.

So far, we have only discussed simple intervals, which span an octave or smaller. Compound intervals are larger than an octave. 9ths, 10ths, 11ths, and 12ths are the most common compound intervals. When you rewrite these, they correspond to an octave plus a 2nd, 3rd, 4th, and 5th.

Usually we refer to compound intervals as simple intervals.  To rename compound intervals, subtract 7 from the compound interval.​

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For example, D4 to E5 is a 9th. If we want to refer to it as a simple interval, we do 9 - 7. That leaves us with 2, or a 2nd. To check our work, we should that D4 to E4 is a 2nd.