** Typically, a fretboard diagram represents the way I play a particular chord in that particular song. There are many different ways to play most of the chords. In fact, I probably use the thumb on my fretting hand more than is advisable. Also, do not be deterred by fancy alterations (e.g., C9b5, Am6). Most of these chords can be simplified by minimizing or ignoring the alterations. For example, C9 or even C7 will do fine in place of C9b5 and Am will adequately substitue for Am6. This is true, of course for all degrees of the scale - not just C or A). About the only two chord types I cannot think of a way to simplify are the diminished and half diminished (the latter is aka as a "minor seven flat five"). Although you can always just play a part of the whole chord.
