Let's have a look at the note wheel.
This simple tool will let us start exploring music theory, and help us to learn the names of the notes we are playing on the fretboard.
Here it is! As you can see, we have 12 notes on the wheel.
Believe it or not, 12 notes is all we have to work with, at least in Western music theory. Some cultures use other methods.
When you move up a fret on the fretboard, you move clockwise around the wheel. If you move down a fret, move counterclockwise.
Assuming you know the names of the strings, that's actually all you need to know to name every note on the fretboard!
Some notes have a simple name consisting of a single letter, and others are a little more confusing.
For starters, let's look at the simple notes. The musical alphabet consists of only seven letters: ABCDEFG.
Now, let's address the more complicated notes. First of all:
The "#" indicates that a note is sharp. Sharp simply means one fret higher than normal.
The "♭" indicates that a note is flat. Flat simply means one fret lower than normal.
So, looking at C and D, we can see that the note in between could be referred to in two ways. C sharp and D flat are both valid names.
Notice that most natural notes (notes that are neither sharp nor flat) have a sharp/flat note between them.
The only exceptions here are B to C, and E to F. These two sets of notes have nothing in between, and as such they are only one fret apart.
If you can remember that, you've got everything you need to memorize the note wheel and you can start using it to name the notes you play on the guitar.