They really listened last night. The hottest ticket in this year's Proms, the biggest music festival in the world, was Placido Domingo making his Prom debut in a concert performance of The Valkyrie, the second instalment of Wagner's Ring cycle. People had been queueing from 8am yesterday in anticipation of the evening's event.
When Domingo took the stage at the Royal Albert Hall to sing the role of Siegmund, you could hear the silence. Only the quietest of imperceptible rustles as the audience followed the translated score could be heard.
But at the end of the first act the 6,000-strong audience erupted in cheers and cries of "Bravo" that lasted several minutes.
Antonio Pappano, the Royal Opera House musical director who was conducting, clapped a hand to Domingo's back to point out that there were even more people clapping from behind the orchestra.
At the conclusion of Act Two, the rapture was greater and applause louder as the crowd began to stamp their feet, registering their delirium at seeing a genuine opera super-star on the stage of the Royal Albert Hall.
Domingo said: "At the beginning of the first act I was really nervous, seeing all the people standing and seeing their faces so close.
"But it was phenomenal, but even better was the public, they were amazing, just amazing. It was like being in the middle of a discotheque, your heart beats so fast. The English are supposed to be reserved people, but not at all, it was the most fantastic response with clapping and tapping on the floor. It is not like a concert hall, it is like an arena.
"My debut at the Proms may be a late one, but I hope to come back."
By the time the orchestra had let rip with a barnstorming "Ride of the Valkyrie", in Act Three, the audience were in no doubt that this had been something very special indeed.
In a series of curtain calls, the orchestra, the Valkyrie and every single soloist was cheered to the rafters.
Nearly the entire audience jumped to its feet when Domingo appeared on stage, looking like a man who, despite a career of rapturous receptions, still could not believe this one. Perhaps he knew how rare it is to get an ovation at the Proms.
And by the time the Welsh-based baritone Bryn Terfel emerged, the foot-stomping had resumed in earnest and virtually everyone was on their feet.
There were laughs when Terfel hugged the woman presenting him with the customary flowers and even more when he threw them into the arms of a concert-goer in the front row.
When Antonio Pappano asked the orchestra to stand for one final bow, the fever pitch was complete.
It was, by universal agreement, a night of triumphs, the applause and cheers continued for 10 minutes and beyond, with Domingo the last soloist to leave the stage, turning his head as he did so to take one final look at the extraordinary scenes in the Royal Albert Hall.
Nicholas Kenyan, head of the BBC Proms, said: "It is absolutely astonishing, I cannot remember a prom with this atmosphere and sense of occasion. To have someone as important as Domingo who has never done something like this is astounding. It is a privilege to stage a performance such as this."
Roger Wright, controller of BBC Radio 3, said: "The thing about hearing a performance like this is it's all about the music. Freed of sets and of costumes you get to hear all sorts of details."
Edward Seckerson, The Independent's opera critic, said: "There is no audience in the world as concentrated, sympathetic and intense as this one, so much so that you can feel the energy that audience are giving to the cast. "