This iTunes-exclusive, four-song pairing of Foo Fighters’ Dave Grohl producing and drumming with country-rock/folk titans the Zac Brown Band has an added bonus in Oteil Burbridge on bass (first seen on the Country Music Awards in November). Burbridge, who counts ZBB drummer and former Peacemaker stickman Chris Fryar among his connections to the group, is in fine form via his vintageFender Precision and Gibson EB-2 (both tuned to Eb). On the medium ballads “All Alright” and “The Muse,” his seeing-eye bass connects his roots melodically while complementing the vocal lines. The 6/8 lope of “Let It Rain” lets Oteil mine the upper registers for Allman Brothers/McCartney-esque feel-good fills. Finally, the driving boogie of “Day of the Dead” finds Oteil (who wrote about the experience in his blog) in full-on groove mode, first locking down and then taking creative liberties with his part.