Interval theory lesson

Toda’s theory lesson will reveal all about intervals, what they are, and how musicians use them, so let’s jump right in.

Contents

What are intervals?

An interval is the name given for the distance between two notes. In Western music, we have a total of twelve possible intervals along with perfect unison which is two notes of the exact same pitch, to make a total of thirteen intervals. Notes above the octave can be named in two different ways, either as the actual interval space ie: perfect eleventh, or as what we call a compound interval ie: compound perfect fourth, which is another way of saying a "perfect fourth above the octave", and is enharmonic to a perfect eleventh.

The quality of an interval may be perfect, major, minor, diminished or augmented just like chords can, and it is common to find intervals written in shorthand, for instance: mi3^rd or m3 for a minor third etc.

Intervals on the guitar

Thankfully, intervals on the guitar are easily remembered as the physical seems to emulate the theoretical. The chart below shows all the available intervals inside one octave, written in both tablature and standard musical notation, and is in the key of A major. I suggest learning each interval until you know them well, as they a key in understanding how to build chords and scales, so you will be using them quite often. Further below you will find audio samples for each interval that will help you differentiate between them, each interval has a unique sound and eventually, you will be expected to name each upon hearing them only, so you had better get practicing!

Interval usage

Intervals are most commonly used to communicate chord and scale formulas, for instance: the formula of a major seventh chord is root/1^st, major 3^rd, perfect 5^th and major 7^th. Sometimes, interval names are shortened from major 3^rd to MA3^rd, or from perfect 5^th to simply P5^th.

Intervals are really the language of scale and chord theory, they are used so often it becomes like a second language to the musician.

Summary

Learning intervals is kind of fun really, the theory is pretty easy and when you start to apply what you have learned you will be glad you put the effort in to learning them.

Cheers & enjoy!