Guitar chord charts, like the one above, are almost as commonly found in guitar music as tablature. The information these chord charts convey, however, is different than guitar tablature. Some of you might look at these chord charts and understand them right away, but it doesn't always "click" for everyone. For the sake of being thorough, let's examine what exactly these guitar chord charts tell us. Note that for the purposes of this instruction, we are assuming that the guitarist is playing a right-handed guitar, strung in the traditional manner.
The Basic Chord Chart Layout
If it's not immediately clear, the chord chart above represents the neck of the guitar. The vertical lines represent each string - the low E string (the thickest one) is on the left, followed by the A, D, G, B and high E string (on the right).
The horizontal lines on the chart represent the metal frets on the neck of the guitar. If the chord chart is depicting the first few frets on the guitar, the top line will generally be bolded (or sometimes there is a double line), which indicates the "nut". If the chord chart is depicting frets higher up on the fretboard, the top line will not be bolded.
In cases where chord charts are representing places higher up on the fretboard, fret numbers will be shown, usually to the left of the sixth string. This provides guitarists with an understanding of which fret the chord shown is to be played at.
If you're still having trouble understanding the basic layout of the image above, then do the following - hold your guitar up to the screen of your computer, so that the strings of the guitar are facing you, and the headstock of the guitar is pointing upwards. The image here represents this same view of your guitar - strings running vertically, with frets running horizontally.
Which Frets to Hold Down
The big black dots on the guitar chord chart represent the strings and frets which should be held down by the fretting hand. The chart above indicates that the second fret of the fourth string should be held down, as should the second fret of the third string, and the first fret of the second string.
Some guitar chord charts indicate the fretting hand fingers that should be used to hold down each note. This information is represented by numbers displayed beside the black dots used to show which frets to play. Learn about the names of the fretting hand fingers here.
Open Strings / Avoid Strings
Above the top horizontal line on the chord chart, you'll often see some X and O symbols over strings which aren't being fretted by the left hand. These symbols represent strings that should be either played open - represented by an "o" - or not played at all - represented by an "x". Whether unplayed strings should be muted or avoided entirely is not represented in guitar chord charts - you'll have to use your judgement. If a string is not being fretted, and has neither an "x" or "o" above that string, assume that the string should not be played.