Green Light producer Jack Antonoff has opened up about Lorde's new hit and his relationship with the Kiwi singer in a series of tweets on Friday morning.
Antonoff, who has written songs with Taylor Swift, Sia and Grimes, detailed everything from how he and Lorde met to praising her as an artist, saying there are "not many living artists" like her.
"[I] met Ella years ago at a Grimes show. We talked about Robyn and drum ideas. Today I feel very proud of every day with her since," he wrote.
"Ella and I made Green Light in [New York City] in my apartment in a very small studio that looks like a club house. Nobody around. Just her and I wondering if we could get away with that chord change when the "I hear sounds" bit begins.
"We saw a show that night before and someone [onstage] was banging a piano in a head-on-fire way. Next day at my house we started thinking about that. I remember going to the kitchen and when I came back, Ella had the "I'll come get my things, but I can't let go" line, and I was just in heaven."
He finished with a final ode to Lorde:
Green Light was also produced by prolific hip-hop producer Frank Dukes, who has worked with an extensive range of artists including J. Cole, Drake and Rihanna.
Antonoff thanked Dukes, as well as Pure Heroine producer Joel Little, who contributed to the song.
Lorde responded to Antonoff with love.
Antonoff also appears briefly in the music video for Green Light, jamming on a piano as Lorde dances in front of a mirror.
His role as producer comes after Joel Little confirmed last year he had stepped back from working on the new album, Melodrama, after assisting with the writing process.
"We wrote together, but I'm not producing the record ... This time I'm coming at it more as a fan than being super involved. I'm excited to see what she's working on," Little told the New Zealand Herald.
He said the singer was "trying to do something different", a sentiment Lorde confirmed to ZM's Fletch, Vaughan & Megan this morning.
"When I first started writing for a new project I was writing a lot of stuff that sounded like Pure Heroine, and I think that happens to all artists. You need to get the last record out of you before you make anything new."