Watch the Three - One Forms online guitar lesson by Brad Carlton from Guitar Lab: The Golden Arp
This lesson covers the Add 9 arpeggio in 2nd inversion. Due to the stretched out nature of this form, we will play it with legato slides between the 3 and 5. Consult ex 8 for the layout. Play the 3 with your 1st finger then slide up to the 5. This interval will always be 3 frets. Next play the root with your 4th finger. Remember that the interval between the 5 and 1 is always a perfect 4th (ascending from 5 to 1). To complete this arpeggio form use your 2nd finger on the next highest string to play the 9(2).
I will demonstrate applying open drone strings in conjunction with this arpeggio form for various rhythm guitar textures.
Explore each measure of ex 8 and notice how measure 5 differs from the others. This is because of the tuning between strings 3 and 2(Major 3rd vs Perfect 4 with all other adjacent strings).