In addition to rousing performances of blues classics and renowned hit songs, many of the most memorable performances saw artists coming together for some stirring collaborations. Among the highlights were the surprise pairing of John Mayer and Keith Urban for the Beatles' "Don't Let Me Down," Vince Gill and Clapton taking on "Lay Down Sally," Keb Mo and Taj Mahal covering the Sleepy John Estes' song, "Diving Duck Blues," Gill performing "Tumbling Dice" with Urban and Albert Lee and members of the Allman Brothers joined forces for a haunting acoustic cover of Neil Young's "The Needle and the Damage Done."