Watch the Blue Sky: Ex. 3a online guitar lesson by Andy Aledort from Kings of Rock & Roll Vol. 3: Duane Allman
The next two solo excerpts are played over a groove and progression inspired by the great Dickey Betts/Allman Brothers classic "Blue Sky," which moves alternately between the I (one) chord, E, and the IV (four) chord, A. The scale that is emphasized here is a twist on a standard E major pentatonic scale (E F# G# B C#) in that the fourth scale degree, A, is included, forming an E major hexatonic scale (E F# G# A B C#). The addition of this one scale degree serves to strengthen the tie to the four chord, A, while offering a greater variety of melodic improvisation.