Bob Dylan's impact on popular music has been incalculable. Having transformed staid folk music into a vehicle for coruscating social commentary, he then swept away the romantic platitudes of rock n roll with his searing intellect. From the zeitgeist-encapsulating protest of Blowin in the Wind to the streetwise venom of Like a Rolling Stone, and from the stunning mid-sixties trilogy of albums Bringing It All Back Home, Highway 61 Revisited and Blonde on Blonde to Time Out of Mind, his stunning if world-weary comeback at the age of 56, Dylans genius has endured, underpinned by the dazzling turn of phrase that has made him the pre-eminent poet of popular music.