Summary: The guitar riff is the DNA of rock 'n' roll, a double helix of repetitive simplicity and fiendish complexity on which its history has been built. From Chuck Berry through to the White Stripes, this documentary traces the ebb and flow of the guitar riff over the last 60 years of popular music. With riffs and stories from an all-star cast including Brian May, Dave Davies, Hank Marvin, Joan Jett, Nile Rodgers, Tony Iommi, Robert Fripp, Johnny Marr, Nancy Wilson, Kevin Shields, Ryan Jarman, Tom Morello and many more.