Intro to Music Theory for guitarists: the 12 notes

learn music theory for guitar



Understand the 12 notes of western music and how they relate to each other

The whole foundation of Western Music is based on the concept of 12 notes. This intro to music theory will help you to understand which notes these are and how to think about the relationship between two notes.


The piano keyboard can help us to visualize these notes

       The 7 white notes (or natural notes) are C, D, E, F, G, A B

       The 5 black notes (sharp notes) are C#, D#, F#, G# and A#

(note C# is pronounced as ‘C sharp’)

1. Keyboard

 Identifying Notes on Guitar

The thickest string on your guitar (which is also the one nearest your face) is an E string. 

Playing this string will yield an E note.


If you now fret this string at:

·      the 1st fret, you get an F note

·      the 2nd  fret, you get an F# note (pronounced F sharp)

·      the 3rd  fret, you get a G note


This thickest and thinnest strings on your guitar are E strings.

The thickest string (called the low E string) plays a lower pitch note.

The thinnest string called the high E string) plays a higher pitch note.



Let’s visualize this first on the piano keyboard and then on the guitar neck

2. Keyboard

Visualizing on the Guitar

I want you to think the following way:

·      The E string plays an E note (obviously)

·      Moving up one fret raises the E note to become an F note (see the red arrow above).

·      Moving up one more fret raises (or sharpens) the F note to become an F# (F sharp) note

·      Moving up one more fret raises the F# note to become a G

Therefore, if you play the Low E string (thickest guitar string) at the 3rd fret, you are playing a G note. And maybe for the first time ever, you now understand why!

Tones and Semi-Tones

As we mentioned above, there are 12 notes in Western Music.

The distance or interval between any two consecutive notes is referred to as a semi-tone.


From our ‘arrows’ above, we saw a distance of a semi-tone between

·      E and F

·      F and F#

·      F# and G

·      And so on….


Unsurprisingly, the distance of two semi-tones is also called a tone.


We see that F to G is a tone apart.

This is because F is consecutive to F# and F# is consecutive to G which is a distance of two semi-tones = one whole tone.


A guitarist can think like this:

     ·      a semi-tone is 1 fret of difference between notes.

     ·      a tone  is 2 frets of difference between notes. 



Play any string at the 1st  fret and then at the 2nd  fret -> that’s a semi-tone between these notes.

Play any string at the 1st  fret and then at the 3rd   fret -> that’s a tone between these notes.

The cycle of notes

You may have noticed the use of letters of the alphabet in naming of the notes.

We have A, B, C, D, E, F and G.


If you had the question about whether after the “G”, there is a “H”, the answer is no.

Rather the notes form a cycle.

So the G will cycle back towards the A to begin again.

(so you’ll see G   G#  A)

4. Cycle

Sharp Notes

The 5 sharp notes are C#, D#, F#, G# and A#

These notes are the black notes on a piano keyboard (you may remember the diagram below!)

1. Keyboard

The best way to understand these sharp notes (black notes) is to think about them as the note in between 2 regular notes (white notes).


Let’s take C# as an example

This is note in-between C and D.

We can think of this C# note (pronounced C sharp) as

·      Raising/sharpening) our C note (moving it up 1 fret) gives us C#

·      Lowering/flattening) our D note (moving it down 1 fret) gives us C#

So this middle note (like all sharp notes) can be thought of as “C sharp” or “D flat”. 

Note that we write D flat as D.


C# and Db are just labels.

This one note can be called either C# or Db 

(whichever you like)

In a similar way, all 5 sharp notes can be considered in this way.


The note between:

A and B = A# or Bb

C and D = C# or Db.

D and E = D# or Eb.

F and G = F# or Gb.

G and A = G# or Ab.




We can reflect this in our cycle of notes (where we update A# as “A#/Bb”)




You will notice that there is no sharp note between B and C and no sharp note between E and F.


There is no note between B and C.

If you move B up a fret, you have C. And if you move C down a fret you get B.

There is no note between E and F.

The same is true for E and F – moving E up a fret gives you an F.


So we need to remember BCEF (B goes straight to C and E goes straight to F) – and if you try and pronounce this, it sounds like Bah-Keff.





1)    What is the E string at the fifth fret

2)    What is the A string at the second fret

3)    What is the D string at the third fret

4)    What is the G string at the second fret

5)    What is the B string at the second fret.

Conclusion - intro to music theory

There are some key concepts in this article.

Feel free to read it several times. Once you can begin to identify the relationship between a couple of notes and how many semi-tones (or frets) are between them, this will all come quickly

Get the Learn Fingerpicking Book

Register for the newsletter and I will send you this book (105 pages) and a free lesson once a month. 

This is the ideal resource for complete beginners who wish to learn guitar.

Scroll to Top