Here's the end lick to get you into the jam for Drifting (taken from 7/3/06 Hartford GRAB show):
Drifting – intro to jam lick:
E --------------------------------------------------------
B ---------15--17-15~----17^18-17--15---------------------
G ---14^16-----------------------------17—16p14^12--------
D --------------------------------------------------12~---
A --------------------------------------------------------
E --------------------------------------------------------
E ------------------------------------
B ------------------------------------
G ---------12-12-------------12-------
D ---12h14------14-12--12h14-----14---
A ------------------------------------
E ------------------------------------
Repeat lick a few times, then into G Mixolydian jam (focuses on the G as well as the D, which is the 5th of G, but add your passing tones & create tension, especially at the end of you solo w/ the 7th tone leading back to the big G to wrap it up & back into the verse chords)