When Tony Bennett topped the bill at Glastonbury festival in 1998, his appearance marked a redemption that 20 years previously would have seemed unimaginable.
Although Bennett later was acknowledged as the only artist to successfully bridge the worlds of pop music and jazz on an international scale for more than 60 years, by the late 1970s he had fallen utterly from grace; he was without a record contract, and deemed quintessentially unfashionable by hip young record buyers. And he was also mired in serious drug problems.
