During the 1960s the company continued to widen its range . Its first Wagner production , Lohengrin , and its first Mozart , The Marriage of Figaro , was both performed in 1962 , conducted by Charles Groves . Another Welsh opera , Hughes 's Serch yw 'r Doctor ( " Love , the Doctor " ) was staged in 1960 . The popular Italian repertoire remained the core of the annual seasons , mostly directed by the head of production , John Moody . Leading roles was taken by rising stars such as John Shirley @-@ Quirk , Gwyneth Jones , Thomas Allen , Josephine Barstow and Margaret Price , the last of whom made her operatic debut with the company in 1962 . Established singers guesting with the company included Geraint Evans who played the title role in Don Pasquale in 1966 , and Ian Wallace in the same part the following year . Evans was also seen as Leporello in Don Giovanni in 1966 and as Falstaff in 1969 .