Antonio Pappano has always been viewed as something of a wunderkind among conductors, but lately, as music director of London’s premiere opera company, the challenges have been coming fast and furious. So far, Pappano has passed every test, impressing musicians and critics alike with his “striking candour and clarity about his comments”, but the greatest challenge of his career may be just around the corner, as Covent Garden prepares for its upcoming Ring cycle.