Mackerras traveled to Europe in 1947 and became a member of the Sadler's Wells opera company orchestra. While in England, he won a British Council Scholarship to become a conducting student of Vaclav Talich
at the Academy of Fine Arts in Prague. During his studies in Czechoslovakia, he developed a lifelong interest in the music of Slavonic composers, especially Leos Janácek
. After his formal training, he returned to Sadler's Wells, where he made his London debut leading Johann Strauss
' Die Fledermaus, and remained on the company's conducting staff until 1954. In 1951 he conducted the British premiere of Janácek
's opera Kát'a Kabanová (1919-1921).
Following his engagement as principal conductor of the BBC Symphony Orchestra
in 1954-1956, Mackerras guest-conducted orchestras in Britain and throughout Europe. In 1963 he conducted at Covent Garden for the first time, leading Shostakovich
's opera Katerina Izmaylova (the revised version of Lady Macbeth of Mtsensk); thereafter, he frequently conducted at the house. From 1966 to 1970 he was the first conductor at the Hamburg State Opera. In 1970 he assumed the position of music director at Sadler's Wells, which changed its name to the English National Opera in 1974. Mackerras returned to Australia in 1973 to conduct the inaugural concert of the new Sydney Opera House and also conducted the production of Mozart
's The Magic Flute during that opening year. He made his Metropolitan Opera
debut in 1974 with Gluck
's Orfeo et Eurydice.
Mackerras' reputation as a specialist in the music of the Classical era began with his Sadler's Wells production of Mozart
's The Marriage of Figaro in 1965, in which he used the results of the burgeoning research into authentic performing styles to correctly perform appogiaturas, and to have the singers ornament their parts in accordance with the practices of Mozart
's day. These and subsequent performances and recordings have been highly influential in shaping the current approach to earlier music, as have Mackerras' editions of Handel
's music. Meanwhile, Mackerras thoroughly researched the music of Janácek
(the published editions of which were unusually prone to errors) and both produced and recorded accurate editions of the Czech composer's music. Mackerras died from cancer in London on July 14, 2010.