Williams said Jackson changed the way people looked at music
Stars including NERD frontman Pharrell Williams, Lily Allen and The Streets singer Mike Skinner have paid tribute to Michael Jackson at Glastonbury.
Williams said at the festival: "The music was so incredible and what he and Quincy Jones did was change music and the way people looked at music."
Allen wore a single white glove for her set on the Pyramid Stage, while The Streets played a cover of Billie Jean.
Gabriella Cilmi also remembered the superstar, singing part of Billie Jean.
The festival got under way in Somerset on Friday, just hours after news of the King of Pop's death spread through the site.
Record producer and rapper Williams said Jackson and Jones - who produced the Thriller album - "opened the door for human beings to explore a higher level of musical consciousness".
Williams, whose band played the Pyramid Stage, told BBC News: "We were supposed to work together. I remember playing some songs for his manager and his manager was like, 'these songs aren't good enough'.
Lily Allen was among the stars on the main stage on the festival's first day
"Whenever I saw Michael after that he would always bring it up. He thought it was so funny."
Festival organiser Emily Eavis called him a "truly great artist", adding: "There will be tributes all over the site, all weekend".
Glastonbury founder Michael Eavis added: "You realise what a fantastic legend we've lost, the like of which we can't really replace.
"As an exponent of song and dance, no-one came close."
A Glastonbury spokesman said there was nothing formal planned to mark Jackson's death, but said: "A lot of the performers will be talking about it during their sets".
Emily and Michael Eavis remember Jackson
BBC Radio 1 presenter Jo Whiley noted a muted mood at Worthy farm on Friday morning.
She said: "Everybody will be celebrating the music of Michael Jackson. You can guarantee tonight there will be loads and loads of Jacko coming out of sound systems here."
Dave McCabe, singer with The Zutons, told the BBC more cover versions were inevitable: "Hopefully, because he's got good songs and it's always a winner."
Tommy Bowen, keyboard player for the band White Lies, who played the Other Stage on Friday, said most of the bands playing the festival "can't help but be touched by what's happened".
He added: "He's such an influential artist, I think many of the people here have been brought up on Michael Jackson.
"His music crosses musical boundaries, it's a big shock."
I'd like to remember him for his music
Felix White, from The Maccabees, who are also playing Glastonbury's Other Stage, agreed but claimed Jackson's death left him with mixed feelings.
He told BBC 6 Music: "It's weird because you kind of feel that he seemed so unable to cope with the world that, you don't want to say that's it's a blessing in disguise, but it's hard to know how to feel about it."
Within hours of the confirmation of his death, some stalls began selling T-shirts printed with Jackson-related slogans including "Jacko RIP 1958-2009" and "I was at Glasto when Jacko died".
David Dawson, who is DJing under the name JazzDJ, said he bought one at about 0300 BST on Friday.
He added: "I'd like to remember him for his music. That's what he should be remembered for."
Many festival-goers learned of the news late last night as stalls scattered around the festival site began playing Jackson tracks.
One fan said: "They started playing loads of his music and we thought, 'Oh, that's really strange' and then someone said, 'Michael Jackson's dead' and we were like, 'No way'."
Another reveller added: "Everyone thought it was a joke at first - then people started watching the news and saw it was true."
Artists including Lady GaGa, Neil Young and The Specials also played at the festival on Friday.
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