This lets the open D string ring.
7th chords use the notes from the major scale: 1, 3, 5, b7
Our second way of playing the E7 Guitar Chord in open position also starts with playing a regular E major chord. This time you add your little finger on the 3rd fret of the B string.
Try using this chords in a Blues progression in A or E and tune back soon for another guitar chord of the day.