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."
Hanks 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 King's praises before she came on stage to sing the first song of the album I Feel The Earth Move.
King 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, King 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.
Goffin, King's daughter with 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, King 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?"
King and Goffin both performed Smackwater Jack with guitars before King 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.
King paused before the hit made famous by Aretha Franklin, Natural Woman, as a film of King when she was young was played on the big screen.
King then duetted with her younger self before visibly emotional 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 King sang hits written for other artists including It Might As Well Rain Until September and Something Good recording by Herman's Hermits.
King sang one new song after the medley before leaving the stage, waving to the crowd.
She then returned to the stage for an encore including the 1962 hit made famous by Little Eva The Loco-Motion.
As the crowd finished joining in with the famous Loco-Motion, King added: "Ladies and gentlemen please join me in welcoming the cast of the West End musical Beautiful - the Carole King musical."
The cast including Cassidy Janson who plays King in the musical at the Aldwych Theatre then sang a rendition of Feel The Earth Move.
King hugged and held hands with Janson before the cast left the stage.
She said: "I am so grateful. It has been a wonderful evening. Thanks so much."
Alone on the stage for the final song, King revisited You've Got A Friend, changing the lyrics for the London crowd.
She sang: "Thanks for coming out to see me. And thanks for welcoming my friend and family. I love you London. Thank you London. You've got a friend."
The petite singer then blew a kiss to the crowd before leaving the stage.