Guitar Music Theory for Beginners

This article is not going to feature flashy pictures of beautiful guitars.  But it is critically important information for any new guitar enthusiast.  The purpose of this article is to introduce some basic guitar music theory concepts that are particularly useful for beginning guitar players.  Certainly not enough to earn you a bachelor’s degree in music theory, but enough to get you moving on your journey of learning and loving to play guitar.

To keep things simple and not too intimidating, I’m going to focus on four fundamental guitar music theory concepts and if you can get your head wrapped around each of these principles, you’ll be amazed at the musical world that opens up for you.  The four basic guitar music theory concepts are:

  1. The Musical Alphabet
  2. Sharps and Flats
  3. Half-Steps and Whole-Steps
  4. The BC/EF Rule

Guitar Music Theory for Beginners – The Musical Alphabet

Guitar music theory literally starts with the ABC’s that you learned as a toddler.  But in a way, it’s even easier because instead of having to remember all 26 letters, you only really have to remember the first 7.  The pattern of these seven notes simply repeat themselves as the pitch of the notes continues to raise or lower.

The musical distance, or interval, between any note in the first sequence and the same letter note in the next repeating sequence is considered an octave.  For reference, these notes are 8 units apart…..just think of an octagon that has 8 sides.  The most basic musical note pattern goes like this:

A  B  C  D  E  F  G  A  B  C  D  E  F  G  A  B  C….

See, you’ve already conquered the first fundamental music theory concept!  Let’s move on to the next one.

Guitar Music Theory for Beginners – Sharps and Flats

OK, so it does get slightly more complex than just the letters A-G repeating themselves.  But it’s not all that complicated.  Most of the basic notes of the musical alphabet contain an extra note between each of the letters.  A useful analogy to understand this concept is to use numbers.  Let’s say that we replace the musical alphabet of A, B, C, D, E, F and G with the numbers 1 through 7.  The equivalent pattern would look like this:

music theory basics

Now, we already know that fractional numbers exist between each integer number (for example, the fraction 1-1/2 exists between the integers 1 and 2).  And the musical alphabet works on a similar basis.  The music theory terms used to describe the “notes between the notes” are sharps and flats, which are formally known musically as accidentals.  Sharps raise the pitch up by a half step, while flats lower the pitch by a half step.  If we add these extra notes to our previous pattern of letter and numbers, we get the following updated sequences:

music theory notes numbers

The lower half of the diagram probably makes perfect sense because everyone knows that between the numbers 1 and 2 is the decimal value 1.5, or written as a fraction 1-1/2.  But what about the strange symbols above and between the notes A and B for example?  The diagram shows “A# Bb” and this requires a bit more explanation.

The symbol to denote a sharp note is “#” and the symbol to denote a flat note is “b”.  So when an A note is raised in pitch by a half step, it is called “A Sharp” and is written as A#.  And when a B note is lowered in pitch by a half step, it is called “B Flat” and written as Bb.  So if you’re asking yourself if A# and Bb are actually the same note (again, based on numbers they both align with 1.5), you’re catching on because they are in fact the same note!

When the same note can be musically “spelled” two different ways, it is called an enharmonic equivalent.  All of the other sharp and flat notes called out above each single letter note are also equivalent.  So C# is musically equivalent to Db, D# is musically equivalent to Eb, and so on and so on…..

If you’re still confused, that’s OK.  I have another analogy that might help you figure this out.  I’m going to use the keys of a piano to describe the exact same concept of sharps and flats.

music theory sharps flats piano

All of the white keys on a piano are natural letter notes, or integers in our number analogy.  And similarly, all of the black keys are accidentals, or sharps and flats as they’re more commonly known.  Hopefully you can now see that the black keys are the “notes between the notes”.

So when I stated earlier that you only had to know 7 letters of the alphabet, it was only partially true.  Because you also need to know the names of the basic sharp and flat notes.  So how many actual notes are there within a single octave?  Remember that an octave is all of the notes starting from any single note and climbing the chromatic scale until the same note is at the next higher or lower pitch.

If you answered twelve, you would be correct!  If you came up with a different answer, start with the letter C on the far-left side of the piano key diagram above.  Count both the white and black keys stopping just before you reach the next C on the right side of the diagram.  Did you count 12 notes?  Now you’re getting it!

Now you may be thinking, wait a minute, I thought this was a guitar website and not a piano website.  Of course, you are correct that this is indeed a guitar website, so how does the concept of natural notes, sharps and flats apply to a guitar?  Pretty easily actually.  And it’s basically the same concept as you just learned for a piano, except that instead of keys being next to each other, the guitar’s frets are next to each other.

guitar music theory notes

Guitar Music Theory for Beginners – Half Steps and Whole Steps

Going back to the piano analogy, the musical interval between any two adjacent keys on a piano is called a half-step, and if you move two keys from whichever key you’re starting on by skipping a note, it’s called a whole-step.

music theory half steps whole steps piano

Once again, the guitar behaves very similarly to the piano because moving one fret up or down the fretboard represents a half-step and skipping over a note and moving up or down two frets on a guitar is a whole-step.

guitar music theory half steps whole steps

Guitar Music Theory for Beginners – The BC/EF Rule

You’ve made it to the last major guitar music theory building block for this article.  And by now, what I’m about to explain should not come as any big surprise and you may have already figured it out.  It’s called the BC/EF Rule and the rule states the following:  Every natural note in the musical alphabet EXCEPT for the notes B & C and E & F have a whole-step between them.  Once again, this concept is easily visualized on a piano keyboard.

guitar music theory bc ef rule

You may have also noticed that in the image further above with the guitar fretboard and the lettered note names on the low E string, that the B and C notes were right next to each other without any sharp or flat note between them.

guitar music theory bc ef rule

And lastly, I need to make an update to one of the earlier images from above, to remove the “extra” accidentals from the diagram that really don’t exist between the B/C and E/F notes.

guitar music theory bc ef rule






Now technically, could you refer to a C note as a B Sharp?  Technically, yes these notes are enharmonic equivalents, along with C Flat, E Sharp and F Flat, but they are rarely ever used in the music world.


If you’ve made it this far, you have now come full circle in the understanding of some basic guitar music theory.  Of course, there is a ton more to learn to master more advanced guitar music theory, but these four key fundamental concepts should be enough to get your journey started for a beginning guitarist and well into the intermediate stage.

Thanks for reading and good luck!