WHEN Andrew Lloyd Webber and Taylor Swift had the opportunity to write a song together for “Cats,” they, well, pounced on it.

“We wrote 90 percent of it pretty much over an afternoon,” Webber tells Variety about his and Swift’s fast-combusting collaboration on “Beautiful Ghosts,” the one brand new song written for the forthcoming movie adaptation of the 1981 stage musical.

They didn’t actually meet up with the intention of writing a new song… at least, not ostensibly. Swift had gone over to Webber’s last December during filming to rehearse her performance of a song she sings in the film, “Macavity the Mystery Cat,” in her supporting role as Bombalurina. But at some point in the afternoon the fact that Webber had written the instrumental basis of a new song came up.

He played it on the piano, she began improvising lyrics and topline vocal elements, and the song now dubbed “Beautiful Ghosts” was nearly done.

“Taylor got to the essence of what the piece is about. It’s not an ordinary lyric,” says Webber, who adds that director Tom Hooper considered her attempt “absolutely extraordinary, because it’s as if she really has understood the central message of the piece.”

It’s said to appear at least three times in the movie. “Beautiful Ghosts” is initially sung halfway through the film by Francesca Hayward, who plays Victoria, the white cat that has been made a central figure in the reimagining of the 1981 stage musical.

It reappears later in a brief reprise, sung by Judi Dench, as “Old Deuteronomy.” Finally, Swift herself will be heard performing it under the end titles.

(SD-Agencies)