Randy Newman had only 90 minutes to rehearse his duet with Taylor Swift.

Toy Story composer Newman and pop superstar Swift surprised attendees at the world premiere of Toy Story 5 earlier this month when they performed a duet of You've Got A Friend In Me and Randy revealed how it all came together at the last minute.

He told Variety: "They asked if I would mind if Taylor Swift did this thing, and I said, 'No one's ever going to say no to her. We had an hour, maybe an hour and a half [to rehearse].

"She knew the song. There wasn't anything to do. I said, 'Do you want to do it in another key?' But she said no."

Meanwhile, Taylor recently revealed she wrote her own song for the film's soundtrack in just eight hours after watching the movie.

She shared a video on X from the day she wrote I Knew It, I Knew You and said: "Been kind of a hectic day. At 11 a.m., went to go see Toy Story 5, got so inspired, got the songwriter zoomies, went home, wrote the end credit song for Toy Story 5. We have now produced it, and I'm doing vocals. It's 6:57 p.m. In two hours, Bob Iger and Tom from Pixar are coming to hear it. We have not recorded it yet. And I think this is one of the most fun days of my life.

"I've always dreamed of getting to write for these characters who I've adored since I was a 5 year old kid watching the first Toy Story movie. I fell instantly in love with Toy Story 5 when I was lucky enough to see it in its early stages, and I wrote this song as soon as I got home from the screening. Sometimes you just know, right?"

Taylor also shared how proud she is to be the only artist to have created music for the franchise other than composer Randy Newman, who wrote the iconic You've Got a Friend in Me theme song for the original Toy Story, which was released in 1995.

In a preview for Disney and ABS's special celebrating the franchise, which was shared on Good Morning America, Taylor said: "I felt wonderful knowing that I had Randy's blessing to write for this film given that I'm the first songwriter to get to partake in the Toy Story world outside of Randy. I was absolutely dazzled by it."

She then appeared to wipe away a tear and said: "Don't mind me. Just really liked the movie."

Taylor's involvement with Toy Story 5 was kept "top secret" and even Tom Hanks - who leads the voice cast as cowboy Woody - was in the dark about it.

He told Variety: "It was top secret. We did not know until, literally, when the moment came. They ushered us into a soundproof room and said, 'Tonight at 9 pm, the true end titles song is going to drop, and it's by Taylor Swift.'

"And I was like, 'You guys kept this from us all?' We saw the movie without [the song], we had some dummy thing in there. They surprised us as well, to a delight.

"That's like saying, 'By the way, Judy Garland is singing 'Over the Rainbow' at the beginning of this.' That kind of thing."

I Knew It, I Knew You sees Taylor return to her country roots, and the lyrics are written from the perspective of cowgirl Jessie.