The 2005 Jammys – held on Apr. 26 at The Theater at Madison Square Garden in New York City – featured a star-studded lineup, with performances by the likes of Peter Frampton, Les Claypool and Mike Gordon.

However, a stand-out moment of the evening came when Buddy Guy invited an eclectic group of musicians to accompany him for a rendition of “Hoochie Coochie Man.”

Guy employed bassist Phil Lesh (who was also serving as the host of the event) and drummer Questlove as the rhythm section. Meanwhile, unannounced guest John Mayer – who at the time was reinventing his records’ sound to incorporate his love of the blues – took the stage as the second guitarist. Mayer had previously made a surprise appearance at the 2002 Jammys.

Check out the video of this incredible collaboration below, and head to the Relix YouTube channel for more videos!