Although you don’t need to read music to play the guitar, you will want to learn how to read chord diagrams. Musicians have developed a few simple tricks, such as chord diagrams, to enable them to communicate such basic ideas as song structure, chord construction, chord progressions, and important rhythmic figures.
Don’t worry — reading a chord diagram is not like reading music; it’s far simpler. All you need to do is understand where to put your fingers to form a chord. The following figure shows a chord chart, the basic element of a chord diagram.
Let's take a look at the anatomy of a chord chart:
In the chord name, a single capital letter, or a single capital followed only by a sharp or flat, represents a major chord — so the chord shown here is E major. Other chords are based on alterations of or additions to the notes in a major chord. For instance, Em is an E minor chord, E7 is an E dominant seventh chord, Emaj7 or EM7 is a major seventh chord, Emin7 or Em7 is an E minor seventh chord, and Em9sus4/G is . . . well, let's just say that chord names only get more complex as you add and alter notes.
The grid of six vertical lines and five horizontal ones represents the guitar fretboard. Think of it as looking straight at the upper part of the guitar's neck from the front.
The vertical lines represent the guitar strings. The vertical line at the far left is the low 6th string, and the right-most vertical line is the high 1st string.
The horizontal lines represent frets. The thick horizontal line at the top represents the nut, where the fretboard ends. So the first fret is actually the second vertical line from the top. (Don’t let the words here confuse you; just look at the guitar.)
The dots that appear on vertical string lines between horizontal fret lines represent notes that you fret.
The numerals directly below each string line (just below the last fret line) indicate which left-hand finger you use to fret that note. On the left hand, 1 = index finger; 2 = middle finger; 3 = ring finger; and 4 = little finger. You don’t use the thumb to fret, except in certain unusual circumstances.
The X or O symbols directly above some string lines indicate strings that you leave open (unfretted) or that you don’t play. An X above a string means that you don’t pick or strike that string with your right hand. An O indicates an open string that you do play.
In most cases, you will deal primarily with chords that fall within only the first four frets of the guitar. Chords that fall within the first four frets typically use open strings, so they’re referred to as open chords. However, in some special cases, a chord will start on a fret other than the first fret. When this happens, a numeral appears to the right of the diagram, next to the top fret line, to indicate on which fret you actually start. (In such cases, the top line is not the nut.)