A guitar interval is the distance between two notes on the guitar fretboard.
If these two notes are being played at the same time we call it a harmonic interval (also called a double stop in guitar terminology). If they’re played after each other we call it a melodic interval.
An interval of an octave is the distance between a pitch (say, the note A, which we’ll use as our default root note in this lesson) and the same pitch an octave higher, as in the example below.
Within the octave we find 12 different intervals which are defined by both size and by quality.
For instance the intervals of A – Bb and A – B are both an interval of a 2nd, since we’re moving from an A to “some kind of B”.
Thus, the size of each interval can be anywhere from 1 – 8.
However A – Bb is a minor 2nd while A – B is a major 2nd.
Major and minor (as well as perfect, augmented and diminished) describe the quality of the interval.
In the next part of this lesson we’ll explore each interval within the octave.
Unison simply means playing the same note, either by striking the note twice, or in a different place on the guitar fretboard.
Both the notes in this example are the exact same note, A.
A very important aspect of interval training is listening to the different sound qualities of each interval.
Some intervals are very consonant. The two notes in the interval seem to be meant to be played together.
Others are very dissonant. The notes don’t seem to be meant to be played together.
Other intervals are somewhere in between.
(Note: This doesn’t make dissonant intervals any less important than consonant intervals since dissonance resolving into consonance is what makes melodies melodic. It’s something the ear loves to hear).
Intervals of a 2nd are among the most dissonant, with the minor 2nd being the most dissonant of the two.
Intervals of a third are much more consonant. They’re very important in music theory and chord construction since the quality of the 3rd determines whether a triad is major or minor.
The A major triad is made of the notes of A C# and E (that is, the root, and the intervals of a major3rd and a perfect 5th) while the A minor triad is made of the notes of A C and E (that is, the root, and the intervals of a minor 3rd and a perfect 5th).
You may notice that the major 3rd interval sounds happier than the minor 3rd, which is the reason why major scales and chords sound happier than minor.
Also, most chords are formed by stacking intervals of a third on each other.
We have two intervals of a fourth – the Perfect 4th, a pretty consonant interval, and the Augmented 4th, an interval so dissonant it has been nicknamed “The devil’s interval”
Using A as the root note, a Perfect 4th interval would be the distance between the notes A and D while the augmented 4th interval would be the distance between A and D#.
While in theory we have two kinds of intervals of a 5th – the Perfect 5th and the diminished 5th, the diminished 5 is simply the enharmonic equivalent of the augmented 4th.
That is, they’re the exact same interval but have a different name.
Thus the only new guitar interval you’ll have to learn here is that of the Perfect 5th.
You’re probably very familiar with the sound of the Perfect 5th since two notes a fifth apart played together are power chords.
Note: Theoretically speaking power chords are not chords since a chord requires 3 or more notes in it. However when used in real music, they can replace chords especially when creating guitar riffs.
Intervals of a 6th are also consonant and have a similar sound quality to intervals of a 3rd.
Intervals of a minor or a major 7th are dissonant intervals. As the name suggests, 7th chords are major and minor triads with the addition of a 7th interval from the root.
The octave is the most consonant interval of all, since it’s actually the same note being played and octave higher.
The intervals given above are all the intervals that can be played within an octave.
Compound intervals are intervals that go further than an octave.
These intervals are actually a repetition of the other intervals being played an octave higher.For instance both major 2nd and major 9th are the intervals of A – B, however the major 9th refers to the note B and octave higher than that of the major 2nd:
The following is a shortcut to find compound intervals:
9th = 2nd
10th = 3rd
11th = 4th
12th = 5th
13th = 6th
14th = 7th
15th = 8th
Guitar intervals exercises
In the next section of this lesson, I will give you a few exercises to help you start putting guitar intervals into practical use.
In this exercise you’re going to choose a guitar interval and play it slowly in different places on the fretboard.
The reason you should play these slowly is to give your ears time to listen. In order to make the best use of intervals you should not only be able to play them on the guitar, but also remember their sound.
There aren’t many – just 12 if you exclude compound intervals. Yet, by memorizing their sound, you would have already gone a long way when it comes to training your ear.
As an example, I’m going to use major thirds.
Note: In the third bar, the pattern for major thirds changes. The reason for this is the way the strings G and B are tuned. Always keep this in mind when playing intervals on these strings and adjust accordingly.
When in doubt if you’ve got the right interval, listen carefully and let your ear guide you.
In the next guitar intervals exercise you’re going to play a sequence of thirds in the A major scale.
Try to identify which thirds are major and which are minor while learning this sequence.
The exercise above can be replicated using any other interval.
As an example we’re going to play a sequence of fourths in the A major scale.
Once again it’s a good idea to try to identify which intervals are perfect 4ths and which are augmented. The dissonance of the augmented 4th interval should make this pretty easy.
Conclusion: How to use this knowledge
In this lesson we’ve covered the theory behind guitar intervals, identified them on the fretboard as well as practiced a few exercises to start developing the muscle memory for each interval.
In reality, when you’re soloing or improvising you’re not thinking in terms of: “Should the next note be a major 3rd or a perfect 4th?”
Not consciously at least.
However, once you internalize these intervals, and see them in the context of the scales and chords you are using, you would actually have these basic musical components stored in your head and, whether consciously or not, you will know the note options you can use in your solos before you even play them.
An important skill you should acquire if you want to compose or improvise music on the guitar.
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