Intervals, the Building Blocks of Harmony

What is an Interval?

Interval is a word describing a pair of two notes, and also the distance between them. The lowest note is the point of reference. This note is the root. We’ll build our framework of how intervals work using only those found in the major scale. Later you’ll see that all of the other intervals can be described and understood in the same way.

An interval has two main traits.

First, the root has its own alphabetic letter, and the upper note has its own alphabetic letter. Counting from the letter of the root to the letter of the upper note, we’ll find the interval numberExpresses the number of letters two notes apart are. Since G and A are two apart (G being 1 and A being 2), the interval number is a second. G# to A or G to A# are also types of seconds, although the first is smaller and the second is larger..

Second, the interval will have an interval qualityOnce we know the interval number, we know the number of steps apart two notes are, roughly. The interval quality tells us specifically the size of the interval. A perfect fifth can be made a little bit bigger (augmented) or smaller (diminished).. It will be described as perfect if the upper note is the fourth, fifth or eighth note of the major scale of the root. All of the other intervals in the major scale are described as major.

Let’s explore the intervals found in the C major scale, and also play them on the guitar.

Let’s take a look at the C major scale, both in “block” form and as a guitar scale climbing up the second string. Remember that the first “C” will be the root. The root is also “1”.

The Major Scale

• play
• pause

Interval Example

What is this interval?

Interval type or number

First, count the root as “1”, and then count up the letter names. If C is 1, then A is 6. Its interval type is 6.

Interval quality

What quality does this interval have? We said that in the major scale, the fourth, fifth and eighth are perfect, and that the others are major.

C to A is an interval called a major sixth. Play this interval on your guitar. It can be played as two separate notes, or they can both be played together. (Later, you’ll see that this is how chords are made.)

Which interval is a perfect fourth? If we count C as 1, that means F is 4. That means C to F is a perfect fourth. Play this on your guitar.

Interval Practice

Practice Naming Intervals

List The Intervals

As the creator of Hub Guitar, Grey has compiled hundreds of guitar lessons, written several books, and filmed hundreds of video lessons. He teaches private lessons in his Boston studio, as well as via video chat through TakeLessons.