Watch the Ring You In 5 online guitar lesson by Brad Carlton from Chord Studies: Open String Chords Vol. 1

Rather than mute that fifth string, lets let it ring out in all of these A, D madd9/A, D m6/9/A and A add9 voicings. You can mute that sixth string with your thumb with some of these voicings or just don’t strike that string when playing -- just don’t let that E string sound out.