This article aims to go a little bit in depth with the Open Triads (or Drop 2 triads)  and it will treat  the concept from both a theoretical point of view and a practical way to arrange them on the guitar fretboard.

What Open Triads are?

Referring to a major triad in close position, 1 3 5, we can obtain a Drop 2 voicing  from it by modifying  its note order. This can be accomplished by lowering an octave the 2nd voice of the triad in close position, so that, from 1 3 5 we obtain 3 1 5.

This 3 1 5 voicing is a Drop 2 major triad in first inversion.

By doing the same with the inversions of the close position voicings, the first inversion 3 5 1 become  5 3 1, and the second inversion 5 1 3 become  1 5 3.

By summarizing we have the following possible six voicings for a major triad:

Close position voicings: 1 3 5,  3 5 1,  5 1 3.

Drop 2 voicings: 1 5 3,  3 1 5,  5 3 1.

Arranging Open Triads on the guitar fretboard

On the guitar these voicings can be arranged on three different ways that correspond to different strings set.

1) placing the bottom voice on a string, separated by the other two voices that belongs to two adjacent strings.

This implies that we can use the following string sets: [6 4 3], [5 3 2], [4 2 1].

2) placing the top voice on a string, separated by the other two voices that belongs to two adjacent strings.

This implies that we can use the following string sets: [6 5 3] , [5 4 2], [4 3 1].

3) placing the voices in non adjacent strings. This implies that we can use the following string sets: [6 4 2], [5 3 1].

The following video show how to obtain drop 2 triads voicings with guitarLayers and how to visualize them on the above mentioned strings sets.