Watch the Drop 2, 4 Voicings online guitar lesson by Brad Carlton from Guitar Lab: The Golden Arp
The drop 2, 4 voicing of the add 9 chord in root position is the subject of this lesson. It is voiced from low to high as follows: 1, 3. 9(2), 5. There are two layouts on the fingerboard for this chord; the 5 4 2 1 string group and the 6 5 3 2 string group. In both fingerings there is a middle string which must not be played (and/or muted). This is an easy to play and useful voicing since the root is the lowest voice.