Welsh baritone Bryn Terfel was forced to "mime" through an entire opera at Covent Garden, after losing his voice hours before the curtain went up.
Bryn Terfel had a throat infection hours before curtain-up
The Royal Opera House was involved in a frantic dash to find a replacement, who stood in the orchestra pit to supply Terfel's "voice".
Veteran bass baritone Sir Donald McIntyre stepped in for the final night of Wagner's Das Rheingold.
He was tracked down at Gatwick Airport as he got off a flight.
The ROH said Terfel, who was diagnosed with a throat infection, was determined not to disappoint the audience and he took the stage as normal.
New-Zealand born Sir Donald was unable to perform the part on stage because he was unfamiliar with Keith Warner's new production. But he knows the role of Wotan well - it is one of his most celebrated roles and one he has performed over the past three decades.
Sir Donald, 70, told BBC Wales: "I'd just landed and my telephone rang. I saw it was my agent. He said 'would you like to sing a performance at Covent Garden tonight'?
"They had been searching for people all day. I don't think I've given a performance from an orchestra pit before!"
Sir Donald said he thought the arrangement might have presented a bigger problem for Terfel on stage.
"I'm sure I didn't do it exactly the same as he did," he said. "I think he could synchronise it because with music it's always in the rhythm and the rhythm is looked after by the conductor.
"I couldn't really hear the other singers. I was under the front of the stage and when they got a little bit back on the stage I was literally unable to hear a thing."
"I actually had my score with me because the orchestra sounded a lot different to what it does normally [from my position]."
The audience for Monday night's performance, which was the last in the production's four-week run, was aware of the replacement.
Sir Donald had a copy of the score with him during the performance from the pit
A ROH spokesman said: "Bryn had a throat infection and the decision was made quite late in the day that he would not be able to sing.
"For major roles such as these there are no understudies so we were faced with finding a performer who knew the role and was of sufficient stature to carry it off."
"Fortunately Sir Donald was available, arguably the greatest living bass baritone.
"It was disappointing for Bryn because it was the last night of the run.
"But the audience were quite excited when they discovered what was happening and it created an extraordinary frisson in the auditorium."