By Caroline Briggs
Entertainment reporter, BBC News at Wembley Stadium, London
Lily Allen kicked off the celebration
Prince Harry kicked off the Concert for Diana with the iconic words "Hello Wembley!"
He and Prince William organised the event to celebrate the life of their mother, Princess Diana, on what would have been her 46th birthday.
Weeks of wet weather cleared on cue over the new stadium, allowing the sunshine to set the perfect scene for a party.
Introducing Lily Allen, Hollywood veteran Dennis Hopper summed up the early spirit: "This is a party. This is a celebration, and you're going to love it."
And love it they did.
The strength of the new stadium was tested as 63,000 people jumped to their feet for Allen's cheery rendition of LDN.
Some danced, all cheered, and somewhere near the stage two giant inflatable daffodils bobbed in time to the music.
Rod Stewart performed a number of his best known hits
Allen was one of many younger performers who were still at school when Princess Diana died in a car crash in 1997.
While acts like Rod Stewart, Duran Duran and Roger Hodgson of Supertramp were some of the Princess's personal favourites, Allen was among her son's choices.
She joined P Diddy, Pharrell Williams, Orson, James Morrison, Joss Stone, Kanye West, Nelly Furtado, Will Young and Natasha Bedingfield on an eclectic bill.
The result was a mix of music to suit all tastes - rappers, rockers and pop-lovers alike.
There were hands in the air for Rod Stewart's Sailing, the inevitable screams for Take That and dancing for rapper West.
Many of the day's stars dedicated songs to the late princess, including Duran Duran, Black Eyed Peas singer Fergie and P Diddy, who sang his 1998 hit Missing You in her memory.
A huge cheer went up for 24 actor Kiefer Sutherland, who was among many famous faces who introduced the artists.
"We get to celebrate Diana through the music she loved by the musicians she admired," he said.
Sutherland introduced The Feeling, who opened their lively set with Fill My Little World.
P Diddy added an international flavour to the party
A glimpse of Prince Harry dancing along to I Love It When You Call had the crowd craning their necks away from the stage and up to the Royal seating area.
Status Quo brought echoes of their iconic Live Aid performance of 1985 to the new Wembley after the interval with Rockin' All Over The World.
And Joe Perry of Aerosmith joined a sky-blue suited and booted Sir Tom Jones on stage for a rendition of Kiss.
The Welsh legend proved to be one of the day's highlights, and drove the two inflatable daffodils crazy by belting out Ain't That a Lot of Love and the Arctic Monkeys' I Bet You Look Good On the Dancefloor.
As the sky over Wembley began to darken, Rod Stewart lit up the concert with some of his best-known hits - Maggie May, Baby Jane and Sailing.
In honour of Diana's love of dance and musical theatre, there was a performance of an act from Swan Lake by the English National Ballet, and songs by Andrew Lloyd Webber.
TV presenter Cat Deeley introduced a medley of songs from some of Lord Lloyd-Webber's hit musicals.
How Do You Solve A Problem Like Maria? winner Connie Fisher sang Memory from Cats, while Italian tenor Andrea Bocelli and Sarah Brightman also took to the stage.
The audience provided the "ah-ahs" as Donny Osmond, then Jason Donovan, and finally Lee Mead, dressed in his Technicolor Dreamcoat, performed Any Dream Will Do.
Osmond and Donovan have famously played Joseph on stage, and Mead is to do so in the West End in a few weeks, having won BBC One talent show Any Dream Will Do.
Take That, one of Princess Diana's favourite bands, opened their eagerly anticipated set with an energetic version of Shine, followed by Patience and a crowd sing-a-long to Back for Good.
It was left to Sir Elton John to bring the music to an end with hits like Saturday Night's Alright for Fighting and Tiny Dancer.
Lee Mead belted out Any Dream Will Do from the Joseph musical
But, after a video tribute by Nelson Mandela, it was Diana herself who brought the evening to a poignant close.
Never-seen-before home movie footage of her as a child was shown on the giant screens that flanked the main stage.
The audience, many in tears, watched images of Diana's christening and her first birthday party, to a soundtrack of Freddie Mercury singing Those Were the Days (Of Our Lives).
It was a memorable end to a memorable day for an unforgettable icon.