Watch the 1 5 6 Structures online guitar lesson by Brad Carlton from Guitar Lab: Open String Universe

This lesson uses a root fifth sixth structure on the 5th, 4th and 3rd strings combined with the 2nd and 1st strings open. Voicing 1 is a CMaj 7/6 voiced 1 5 6 7 3. Ionian and lydian scales apply. Voicing 2 is a C#m 7/6 voiced 1 5 6 b7 b3. Dorian and melodic minor apply. You could also view this chord as a C#13 #9 (no 3). The half-whole diminished scale would then be applicable. Voicing 3 is a D 6/9 (no 3) voiced 1 5 6 6 9. Ionian, dorian, lydian, mixolydian, overtone and meldoic minor would all apply. Voicing 4 is an E6 (no 3) voiced 1 5 6 5 1. Ionian, dorian, lydian, mixolydian, overtone, melodic minor and half-whole diminished all apply. Voicing 5 is an FMaj 7/6 #11 (no 3) voiced 1 5 6 #4 7. Lydian is the scale for this chord. Voicing 6 is an F# 7/6 sus4 voiced 1 5 6 4 b7. Dorian and mixolydian apply. Voicing 7 is a G6 voiced 1 5 6 3 6. Ionian, lydian, mixolydian, overtone and half-whole diminished all apply. Voicing 8 is an A 6/9 (no 3) voiced 1 5 6 2 5. Ionian, dorian, lydian, mixolydian, overtone and melodic minor apply.