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 1st inv. in a "three-one" form. Look at example 7 and you will see an EAdd 9 arpeggio. Measures 1, 2, 3 and 4 maintain the same shape on the fingerboard because of the consistent perfect 4th tuning that occurs between the string being used. The shape changes in measure 5 because of the major third interval between strings 3 and 2.

This 1st inv. three-one form involves some stretching. Your 1st finger will play the 9(2), your 2nd finger plays the 3 (one whole step higher) and your 3rd finger plays the 5(3 frets higher). The challenge then occurs with the ascending finger roll needed with the 4th finger to complete the arpeggio. The root will always be this note on the next highest string. Use that as your locator for positioning your hand on the fingerboard. (Thinking right to left on the neck). On first impression, this particular inversion of the three-one form may not be a favorite of yours, but it is very effective in fusion style and hard rock/neoclassical shred styles.