The show must go on

The London premiere of George Benjamin's "Into the Little Hill," a chamber opera on the tale of the Pied Piper, had been under way for 10 minutes when the lights went out in Linbury Theatre at the Royal Opera House, Covent Garden. Patrons adjourned to the bar to wait for power to be restored. They kept waiting, and, presumably, kept drinking. Finally, the composer, two-person cast and London Sinfonietta trooped in to perform the opera in the bar.

"Soprano Claire Booth improvised by sitting on the bar itself among the unwashed glasses and the performance finished with enthusiastic applause," Alan Rusbridger reports in The Guardian:

http://www.guardian.co.uk/music/2009/feb/15/royal-opera-house-power-cut