The fully CAGED guitarist soon realizes that the open D chord shape is, in reality, a truncated version of the open C shape. If one were to extend the open D to a Barre chord, that should become clear.

For example, if you were to place the Capo on the 2nd fret and then play the open C shape, it would sound as a D Major. Note the fretting of the top three strings is identical at that point, it is just that the Capo now takes the place of the 2nd fret fingers.


--Mac