In 1960, Davis made his début at the Proms in a programme of Britten, Schumann, Mozart and Berlioz. In the same year, he was appointed chief conductor of Sadler's Wells Opera, and in 1961 he was made musical director of the company, with whom he built up a large repertoire of operas, conducting in London and on tour. "Grove's Dictionary of Music and Musicians" wrote of this period, "He excelled in "Idomeneo", "The Rake's Progress" and "Oedipus rex", and "Fidelio"; his Wagner, Verdi and Puccini were less successful. He introduced Weill's "Mahagonny", and Pizzetti's "Assassinio nella cattedrale" to the British public and conducted the première of Bennett's "The Mines of Sulphur" (1965)." Together with the stage director Glen Byam Shaw, he worked to present operas in a way that gave due weight to the drama as well as the music. In his early years, Davis was known as something of a firebrand with a short fuse in rehearsals, and his departure from Sadler's Wells in 1965 was not without acrimony.