Finding Notes on the Fretboard

The Open Strings

As you may know if you play the guitar, the open strings are E, A, D, G, B, and E (Eddie Ate Dynamite, Good-Bye Eddie!). We can represent these with a chart like this:

The open strings of the guitar

The lowercase "e" is for the high E string, so we can differentiate it from the low "E."

Whole Steps and Half Steps

To find notes above the open strings, we first need to understand "Whole Steps" and "Half Steps." A half step is the smallest distance in pitch we can travel¹ using our Western tuning system. On the guitar, that distance is simply one fret. For example, from the second fret to the third fret is a half step, and from the first fret to the open string (fret number "zero") is a half step. A whole step is simply two half steps.

Every note has a whole step gap above it, with the exception of B and E, where it's a half step. They're comfortable "BE"ing themselves.

The A String

Let's start with the A string. It seems like a natural choice, as A is the first letter of our musical alphabet. To map out the notes on the frets above it, we can follow our rule: every note has a whole step gap above it. This brings us up to the note B on the second fret.

From A to B is a whole step

To find the next note, we have to use our exception: B and E only have half-step gaps above them. This is the note B, so therefore ascending to the note C will take us up a half step.

From B to C is a half step

We can repeat this process through the length of the string. C to D is a whole step, D to E is a whole step, E to F is a half step (remember, B and E!), F to G is a whole step.

The notes on the A string

I've flipped the chart 90 degrees to more comfortably fit it on the page. 

At this point, logic would dictate that the next note up be H, however there is no H in music. This is the point where our musical alphabet ends, and starts again at A, which is a whole step above G.

The notes on the A string, up to and including the 12th fret

We can repeat this process on each string, giving us the following map of the fretboard:

The notes on the fretboard

This process works for any string instrument; guitar, bass, ukulele, mandolin, and even the violin (although the frets are "invisible")!

At this point it might become apparent that the 12th fret notes are always the same as the open strings. The reason for that is because there are twelve total notes in our system of tuning--to borrow terms from the piano, seven "white keys" and five "black keys." Most fretted string instruments have this point where it repeats marked with two dots, to help us remember that everything above here is just a repeat of what's below. 

But just one more thing!

Why does this chart have so many gaps? What's in the spaces between the notes? 

What you seek, my friend, are called accidentals.

Accidentals are how we name notes that don't have letter names on their own. There are two² main types of accidentals: Sharps (♯) and Flats (♭). Sharps raise the pitch of the named note by a half step. Flats lower the named note by a half step. For example, if you want to play the note between A and B, you could call it A# (meaning a half step above A) or you could call it Bb (meaning a half step below B). These are two ways to name the same pitch.

We can raise the note A by a half step to get A#

We can lower the note B by a half step to get Bb

All of this together allows us to find any note on the neck. We can also choose a fret, and find the name of the note that lies on it. This will aid us in our understanding and fluency of the fretboard, and will help us to locate barre chords and scale shapes in any key, freeing us from the open position.

¹ If we account for tuning, glissandi, bending pitches, temperament, microtones, etc. we can get as granular as our ears can pick up, but the half step is commonly known as the smallest distance.

² There are more than this. There's also double sharps (notated as 'x') and double flats (𝄫), which raise or lower a pitch by two half steps, and naturals (♮), which cancel out any accidentals that came before them.