The composer, whose Broadway hits include "Evita," "Cats" and "Phantom of the Opera," will weigh in on the remaining 12 finalists, who are competing to play Danny the slick greaser and Sandy the naive good girl (John Travolta and Olivia Newton-John in the classic 1978 movie version) in the revival of "Grease" coming to Broadway this summer.
The hopefuls — split evenly between guys and girls — will perform songs from Broadway musicals, including Webber's shows, in the two-hour episode (7 p.m. EST).
Newton-John has made two guest appearances on the show, which is hosted by "Access Hollywood" co-anchor Billy Bush and British TV personality and musical star Denise Van Outen.
"Grease" already has had two marathon runs on Broadway. The original production arrived in 1972 and didn't close until 1980, after more than 3,000 performances. The revival, starring Rosie O'Donnell as Betty Rizzo, opened in 1994 and ran for more than 1,500 performances.