I am trying to compare Bob Dylan to anyone else. As a poet, he is not more memorably gifted than Leonard Cohen, Yeats, John Berryman, or indeed Dylan Thomas. As a singer, he is no match for Frank Sinatra, Elvis Presley, or Pavarotti. As a songwriter, he is equalled by, perhaps, John Lennon, Kurt Weill, Kurt Cobain, Bob Marley, and Elvis Costello. Why is it then that he is singled out as the paramount genius of popular music? The answer, my friends, is 50 years. Dylan, that enigmatic, sexy, sly trickster figure has been in constant transformation for fifty years of unequalled song composition and performance, or reperformance, his interpretations and variations creating Borgesian complications. His personal journey has had more make-overs than Lady Gaga. He has been a Christian, a cowboy, a peacenik, a fierce Zionist, and a praiser of Scotland. He is, arguably, the Shakespeare of song - an uncanny talent of unlimited potential. At 20, at 40, and at 70, he amazed and amazes. I do not think he is the presiding genius of our age - our age seems too multiple to have just one. But he is one of the greats. It is good to be able to wish him a happy 70th.