It was exactly the sort of cheer that had been given out for the acts that had just graced the stage, perhaps even louder.
There was a deafening roar as the Queen, resplendent in a golden outfit, made her way to the centre of the stage after the finale of her Diamond Jubilee concert.
Just hours earlier her husband Prince Philip had been taken ill, but she soldiered on, holding fast to her stoic sense of duty.
With Gary Barlow leading the way, and Kylie Minogue following close behind, the monarch was flanked by her son Prince Charles and the Duchess of Cornwall. They were surrounded on all sides by performers who had just taken part in the concert.
A hush descended over the expectant crowds – 18,000 were watching in front of the Palace, and another 250,000 on screens in St James Park and The Mall – as Charles took the microphone to speak.
"Your Majesty, Mummy," he began, drawing a huge smile from the monarch, who looked visibly moved.
"I'm sure you would like to thank all the wonderful people who made tonight possible."
The heir had a special mention for the comedians, and their "jolly good jokes" and the 600 technicians working behind the scenes.
"And thanks to Gary Barlow for making this whole thing possible."
He added: "If I may say so, thank God the weather turned out fine."
Charles also mentioned Prince Philip, who was unable to attend after being admitted to hospital with a bladder infection.
"The only sad thing is my father couldn't be here," he said. "But if we shout loud enough, he might just hear us."
At this point the audience started chanting "Philip, Philip, Philip".
Charles continued: "You Majesty, a Diamond Jubilee is a huge event and some of us have had the pleasure of celebrating three Jubilees with you – I have the medals to prove it."
"I was only three when my grandfather King George VI died. You were only 26 when you were given such a huge responsibility.
Tonight is a chance for the nation to give thanks… Thanks for making us proud to be British.
"Proud at a time when our fellow countrymen are suffering so much hardship."
He then led the spectators in giving "a resounding three cheers for Her Majesty the Queen."
Before the National Anthem was played, there was a touching moment as Charles kissed his mother's hand.
Prince Charles' tribute to his mother
'I am sure you would want me to thank, on your behalf all the wonderful people who have made today possible. All the performers, the artists, the musicians, the comedians that made such jolly good jokes, Gary Barlow for helping to make the whole thing possible.
'And all those remarkable technicians all 600 of them behind the scenes without which nothing would happen. 'And if I may say so Your Majesty thank God the weather turned out fine. And the reason of course is because I didn't do the weather forecast.
'Your Majesty, millions we are told dream of having tea with you. Quite a lot nearly had a picnic with you in the garden of Buckingham Palace.
'The only sad thing about this evening is that my father could not be here with us because unfortunately he was taken unwell.
'But ladies and gentlemen if we shout loud enough he might just hear us in hospital and get better.
'Your Majesty a Diamond Jubilee is a unique and special event. Some of us have had the joy of celebrating three Jubilees with you. And I have the medals to prove it. And we are now celebrating the life and service of a very special person over the last 60 years.
'I was three when my grandfather George VI died and suddenly, unexpectedly, you and my father's lives were irrevocably changed when you were only 26.
‘So as a nation this is our opportunity to thank you and my father for always being there for us.
‘For inspiring us with your selfless duty and service and for making us proud to be British.
'Proud at a time when I know how many of your fellow countrymen are suffering such hardships and difficulties. Proud to be lining the banks of the Thames in their millions, despite the rain and the cold. Proud to be part of something as unique as the Commonwealth, which through your leadership has given us that essential sense of unity through diversity.
'So Your Majesty we offer you our humble duty and with it three resounding cheers.