Sir Charles made his operatic d???but with the Royal Opera House, Covent Garden in 1964, where he since conducted 34 operas, including Un Ballo in Maschera which celebrated his 50th anniversary and 80th birthday in 2005. 2002 marked Sir Charles' 50th year with the Edinburgh Festival, in which he conducted Donizetti's Maria Stuarda, Handel's Jeptha and Mozart's Gran Partita.