Sadly, John Martyn died on January 29th 2009. I first saw him live at Les Cousins in Greek Street in London in around 1969 after his second album "The Tumbler" was released. I then spent weeks learning how to play "Seven Black Roses". The first album was 1967's "London Conversation". Here is the official John Martyn website. I would recommend the "Solid Air" & "Grace and Danger" albums as a starting point. In February 2008, he received the lifetime achievement award at the BBC Radio 2 Folk awards, and he was awarded the OBE in the 2009 New Years Honors list. Eric Clapton once said of him that he was "so far ahead of everything, it's almost inconceivable."