Sir Elton John and Tom Hanks were among the famous faces who paid tribute to Carole King in a video as she came on stage to play her album Tapestry in its entirety for the first time ever.
The video celebrating 45 years of the album which won four Grammys was played before the 74-year-old singer-songwriter came into the stage mouthing "Oh my God" to the 50,000 strong crowd as the sun set over Hyde Park in London.
Sir Elton said: "She's the quintessential singer-songwriter. I can't thank her enough because without her I would have never wanted to write songs. I always wanted to write songs like Gerry Goffin and Carole King."
Tom added: "There wasn't a woman on the planet earth that, sometimes even your mum, who didn't take Tapestry and hold the album to their heart and say this is real."
Other stars including Graham Nash, Lou Adler, James Taylor, Barry Mann, Cynthia Weil and David Crosby also sang Carole's praises before she came on stage to sing the first song of the album, I Feel The Earth Move.
Carole dedicated the second song So Far Away to her friend, musician Taylor, as she sang songs from the album in the order they appear.
Before singing Where You Lead, she explained the lyrics had been rewritten for the theme song of US TV series Gilmore Girls to suit mother and daughter, before bringing her daughter Louise Goffin, who played earlier in the day, on stage.
Louise, Carole's daughter with the the late Gerry Goffin, stayed on stage to sing Will You Still Love Me Tomorrow, during which her bass player paused to wipe tears from his eyes.
Introducing the song, Carole said: "This is the first song that her father and I wrote together. The first time I heard it, and this will show my age, was in a 1956 Mercury."
She then moved from the piano, took her jacket off to reveal a black and silver sequin top before picking up a guitar, shouting to the crowd: "Are you ready to get down?"
The pair both performed Smackwater Jack with guitars before Carole returned to the piano.
After exhaling to show she was out of breath, she said: "So, this is what 74 looks like", which was met with extended applause and cheers from the crowd.
Carole paused before the hit made famous by Aretha Franklin, Natural Woman, as a film of Carole when she was young was played on the big screen.
The star then duetted with her younger self before she wiped back tears, saying "thank you, thank you so much".
She then introduced her band before asking them to leave the stage, saying: "I need a moment alone with the audience."
She continued: "So before Tapestry I had this other career in which I wrote a lot of songs with Gerry Goffin and we wrote for other artists. I would like to do a medley of bits and pieces."
She then paid tribute to Goffin, who died on June 19 2014: "It's been two years. He's with us tonight. He's still with us, isn't he?"
The crowd cheered "yes" before Carole sang hits written for other artists including It Might As Well Rain Until September and Something Good recorded by Herman's Hermits.