Davis' early months in charge at Covent Garden were marked by dissatisfaction among some of the audience, and booing was heard at a "disastrous" "Nabucco" in 1972. His conducting of Wagner's "Ring" cycle was at first compared unfavourably with that of his predecessor. Among his successes were Berlioz's massive "Les Troyens" (with Jon Vickers and Anja Silja) and "Benvenuto Cellini", Verdi's "Falstaff", the major Mozart operas, and, as one critic put it, he "confirmed his preeminence as a Britten and Stravinsky interpreter" with productions of "Peter Grimes" and "The Rake's Progress". Davis conducted more than 30 operas during his fifteen-year tenure, but "since people like Maazel, Abbado and Muti would only come for new productions", Davis yielded the baton to these foreign conductors, giving up the chance to conduct several major operas, including "Der Rosenkavalier", "Rigoletto" and "Aida".