The big voices of the show deftly handled material from the composer of "Phantom Of The Opera" and "Jesus Christ Superstar." Gentler singers, however, failed to impress.
Before the competition began, judges Paula Abdul, Randy Jackson, and Simon Cowell agreed that it would be the finalists' toughest night of the season.
Webber predicted that the first singer, Syesha Mercado, would bring the house down with her sassy version of "One Rock And Roll Too Many" from "Starlight Express."
He was right.
Showing more personality than she has in any of her previous performances, the 21-year-old from Sarasota, Fla. started the number perched on top of a grand piano and then jumped down to work the stage.
Jackson said it was her best performance to date and told her she could be a huge Broadway star.
Dreadlocked Jason Castro had never seen "Cats" - or any Andrew Lloyd Webber musical - but that didn't stop him from choosing the show's most famous song "Memory." The song is written for an aging female character and is usually a tour de force for the woman who sings it.
The 20-year-old Castro, however, isn't aging, female or vocally powerful. Jackson said it was a trainwreck.
A nervous Brooke White didn't fare much better, committing the "American Idol" cardinal sin: forgetting the lyrics.
White, 24, sang the first few notes of "You Must Love Me" from the film version of "Evita" before losing her place. She stopped the music and told the orchestra leader she had to start over. The judges disagreed on her decision, with Abdul scolding her and Cowell saying restarting was a very brave thing to do.
Unlike Castro, 17-year-old David Archuleta did quite well with a song originally written for a woman. His solid pop ballad version of "Think Of Me" from "Phantom Of The Opera" was praised by Jackson and Abdul, although Cowell wasn't quite as impressed.
The next contestant, Carly Smithson, almost made a serious error in song choice, but Webber steered her out of trouble.
When she first met with Webber, the 24-year-old tattooed rocker started singing the ballad "All I Ask Of You" from "Phantom Of The Opera." The composer stopped her before she even got to the second verse, and had her sing the title song from "Jesus Christ Superstar."
He was right again.
Smithson's powerful version of the gospel rock number - which was written for the character of Judas in the play - suited her big voice and was perhaps her best of the season. After Cowell said it was one of his favorite performances of the night, a grinning Smithson held up a t-shirt that read "Simon Loves Me (This Week)."
After an evening of boys singing girls' songs and operatic numbers being turned into pop ballads, rocker David Cook played it straight by nailing a Broadway-worthy version of "Music Of The Night" from "Phantom Of The Opera."
It turns out that Cook, who's known for turning out rock versions of whatever song is thrown at him, has a musical theater background. Proving that he is both a strong technician and a fine interpreter of dramatic song, Cook hit both the powerful and gentle notes with equal passion.
The contestants return to Fox Wednesday night to find out who will be voted off the show.
By Judy Rosen