Who Needs Guitar Theory Anyway?

​Understanding intervals will help you move easily and with confidence around the guitar neck. When I say “understand” I mean both intellectually and with your ear. The best way to do this is to practice this material in this lesson until it becomes 2nd nature. Guitar theory is only useful when it becomes integrated with your practice and playing.

What Are Intervals?

The distance between two notes is called the “interval”. Scales and chords are composed of intervals. The type of scale depends on the intervals between the notes one after the other. The type of chord depends on the interval of the notes, one stacked on top of the other and played at the same time.

Let’s start with the smallest distance between notes. We’ll use the words half step and whole step to describe this distance or interval, though you’ll also see the words semi-tone and tone used for the same thing. The half step (or semi-tone) is the smallest measurable unit we generally use,  and two half steps make up a whole step (or tone).

The interval between the notes A and B is a whole step. If you look at a piano keyboard you’ll see that there is a black key in between the A and B. The interval (distance) from C to D is a whole step. You’ll see the same thing on the keyboard – a black key between C and D. That black key could be called C#. The interval between C and C# is a half step. The interval from F to F# is a half step. The interval from G down to Gb is also a half step.

Gb is another name for the note F#. We can say that F# is enharmonic to Gb.

The Musical Alphabet

There are two places in the musical alphabet that there is no sharp or flat – between B and C; and between E and F. Another way to say this is there is already a half step interval between these notes. No room for a sharp or flat note. I you look at the piano keyboard again you’ll see there is no black key between these notes.

You could say the musical alphabet really looks like this:

A – A# (Bb) – B – C – C# (Db) – D – D# (Eb) – E – F – F#(Gb) – G – G# (Ab)…

The notes in parenthesis are enharmonic to the note to the left and sound the same. They just look different when you write them.

Now Apply To The Guitar

Let’s apply this to the guitar. Play a single note on the guitar and then play the note one fret up. That interval is a half step. Now play a note two frets up. That’s a whole step. A half step is equal to one fret on the guitar. A whole step is equal to two frets. You can play a note that’s one fret down and that would also be a half step. A half step down. Two frets would be a whole step down. Got it?

(I’ll also include in parenthesis the common names that musicians use for these intervals).

• 1 Fret = ½ Step (minor 2nd)
• 2 Frets = Whole Step (major 2nd)
• 3 Frets = 1 ½ Steps (minor 3rd)

and so on…

Yes, there are more intervals besides the half step and whole step. More to come.

This information gives you the foundation and terminology that will help you get started with understanding intervals, scales, chords and other aspects of music.