In terms of drama at the opera, it will be difficult to surpass Tuesday’s performance of Giacomo Puccini’s Turandot after a tenor became unwell leading to a surprise substitution. A Royal Opera House chief, dressed in a jumper, chinos and trainers, deputised in the lead role after French tenor Roberto Alagna, playing Prince Calàf, became ill after the second act. Photograph: PRHowever, the improvisation led to some audience members booing, upset about missing out on Nessun Dorma, the Times reported. As the role of Calàf is specialised, major opera houses will not typically have a cover standing by for every performance. His student, Franco Alfano, wrote a completion that reprised the famous Nessun Dorma aria.