WHEN the new movie Walk the Line about the life of Johnny Cash opens in London next week, cinema-goers will be treated to a selection of his songs in London Underground stations. Buskers are being hired for £40 a day to sing Cash’s hits as part of a marketing ploy to sell CDs. Record companies have discovered that one of the best ways to promote a new release is to pay buskers to sing its songs to some of the 3m people who use the Tube each day. The stunt will surprise many travellers who believe buskers are enterprising musicians...