Add a Finger to Your A Chord

First let's take a look at an easy way to embellish your open A chord. By adding your 3rd finger to the 3rd fret of the B string, you create a "sus 4" sound.

"Sus 4" means that the 3rd of the chord has been "suspended" and replaced with the 4. This creates a tense sound, and you resolve it by removing your 3rd finger and going back to the voicing with the 3rd.