The musical alphabet starts on A and stops at, then starts over back to A. Most letters are connected with an in-between note, these connector notes are called sharps or flats. It's important to remember that there is not a note between B and C, or between E and F. All other notes have a sharp or flat in between them. Take a look at the diagram below.
A String Notes
On the guitar, each fret is a half-step (sometimes called semitone) as you move up the neck. If we start on A, and count up each fret, we have 12 total notes until we get back to A. Here is what that looks like on the guitar’s A string.
The easiest way to think about sharps and flats is by visualizing a piano keyboard. The sharps and flats are black keys. If we start at A and move to the right we can see how we progress through the alphabet, from A back to A.