Adam Lambert, Allison Iraheta Shine On 'American Idol' Rock Night

Resident rockers join forces for a duet, as do Danny Gokey and Kris Allen.

When it gets down to the top four on "American Idol," there is no need to add any extra drama to the equation. But, just hours before Danny Gokey, Allison Iraheta, Kris Allen and Adam Lambert took the stage for Tuesday night's (April 5) rock-themed show, the program's stage manager, Debbie Williams, was rushed to the hospital after tumbling down the iconic center stairs, and the studio was evacuated when a set piece collapsed and sent glass flying everywhere.

The result? The top four [article id="1610707"]didn't a get a chance for a proper run-through[/article] of their songs, but as Seacrest said at the top of the program, "The show must go on." And, frankly, they didn't sound any worse for the wear as the show added yet another twist to this unconventional season: duets. (Check out Jim Cantiello's "American Idol" live blog for a minute-by-minute take on the show.)

With guest mentor Slash, the iconic guitarist for Guns N' Roses and Velvet Revolver, in the house, the remaining quartet got their pep talks this week at legendary Los Angeles rock club the Roxy.

First up was this year's resident male rocker, Lambert, who bit off a huge chunk of rock history by choosing [article id="1610709"]Led Zeppelin's "Whole Lotta Love."[/article] Promising to "kill it," Lambert took the stage in a studded black leather jacket and black jeans and his signature sneer, slinking back and forth as he unleashed a series of bluesy falsetto wails, ending with a gut-busting high note that drew a standing ovation.

"This is the Adam that I love, dude. ... Nobody's gonna ever think about Broadway or any of that stuff. You are a rock star tonight," Randy Jackson enthused about the first-ever performance of a Zeppelin song on the show. Kara DioGuardi took it a step further, saying, "You are more than a rock star, you are a rock god," suggesting he should make an album that mixes classic '70s rock with glam rock and Nine Inch Nails. "It's your lane — kill it!" she screamed.

Paula Abdul called him a "whole lotta perfect," and Simon Cowell joked that the performance was a bit understated. He noted that taking on one of the best rock songs of all time could have been a disaster, but instead it was one of his favorite performances from Lambert so far and one unlikely to be topped.

Allison Iraheta, the season's other rocker, chose a song that perfectly fit what Slash called her "natural rock-and-roll mannerism and swagger": Janis Joplin's "Cry Baby." With a multi-layered, fire-engine red, 1980s hair-metal hairdo, courtesy of Lambert's stylist, Iraheta fell immediately into the pocket, tapping into the late blues belter's underlying pain and grit, serving up aching verses and then exploding with a soulful wail on the chorus.

Jackson didn't love the song choice, saying it didn't show off the 17-year-old singer's formidable range, while Kara said it was the right choice of artist, though she might have picked a different Joplin song. Noting that Iraheta has been knocked for a perceived lack of personality while performing, Kara said she saw the teen's personality shine through. Abdul called her "downright fearless" and suggested that if the long-gestating Joplin biopic ever gets made, Iraheta should be the star. Cowell said Iraheta had shown "staggering" growth over the past eight weeks and praised her confidence, while dissing her for sounding too much like the original.

'American Idol' Top 4 Perform On Rock Night

Next came the first duet segment in the finals, which awkwardly paired Gokey and Allen on a cover of Styx's "Renegade." The two, whose grit-and-glass voices sounded smooth together at first, traded off lines during the verses, with Allen showing a bit more of an edge than he's previously displayed and Gokey singing over him during the choruses.

"I really like the harmonies. I think you guys complement each other greatly with that song," Randy said, noting that the individual vocals were not as strong. Kara thought it was funny that "the guys that help the little women cross the street" were singing a song called "Renegade." "The sum of the parts was better," she said, suggesting that maybe they couldn't hear their own vocals at times, which led to some pitchiness. Paula had no such complaints, calling their duet "powerful" and "compelling," though Simon seemed unimpressed, nonchalantly saying, "Danny, you were better than Kris."

Allen got a chance to shine alone next, and, like Lambert, he went for the big score, choosing "Come Together" by the Beatles. He got to borrow one of Slash's guitars during the mentoring session, admitting he almost "peed his pants" at the chance. Strumming one of his own on the show, Allen added his blue-eyed soul to the heavy Fab Four rocker, showing a bit more attitude.

Randy appreciated that Allen was able to still be himself in a genre he isn't known for, even if the vocals weren't great, but professed to being blown away by Allen's guitar playing. Kara wasn't as convinced, saying she appreciated that the soft rocker tried to bring a harder edge, but "for me, this was not a great performance. ... It was trying too hard. It wasn't the best song." Simon said bluntly, "I didn't like it that much. It was rather like eating ice for lunch, which is it will leave you with nothing to remember afterwards." Simon also called it a safe, boring "jam," which, as he predicted, did not top Lambert.

The final solo performance came from Gokey, who chose Aerosmith's legendary AM radio classic "Dream On." Known for his gospel-tinged crooning, Gokey appeared to struggle to add some grit to his voice at first but then settled into a powerful blues delivery, appearing to run out of steam for the iconic scream at the end, which sounded strained and awkward.

The judges were mixed, with Randy giving him an A-plus for effort in a genre that is not his strong suit. Kara wondered if Gokey took previous comments about his lack of swagger too seriously and maybe pushed things a little too far this week.

Paula is still a huge fan but wasn't feeling the song choice, and Simon agreed with the other three that Gokey took some chances. "But the last note, it was like watching a horror movie," he said. "It was actually a little over-the-top, where I think with Adam it kind of worked; with you, it didn't work so much."

Despite all that, Cowell predicted that Gokey would be safe.

The show ended with the night's second duet: Iraheta and Lambert taking on Foghat's greasy 1975 rocker "Slowride." With Iraheta singing in her chesty lower register and Lambert complementing her with his high squeal (and some seriously tight striped pants), the pair looked and sounded very comfortable singing together. They each worked the audience individually but made time to lock eyes occasionally and ended the song with their faces just a few feet apart as they held a big note and shared a warm hug.

"You guys are our two seasoned rock stars," Randy enthused, saying they should do a duet on their respective albums. Kara called them a rock god and goddess and praised the pair for pushing one another to be better, while Simon declared them the unequivocal winners of the duet-off. "Completely different than the other one, and actually, Adam, you may have given this one [Iraheta] a chance in the competition because of that."

Wednesday night's results show will feature performances from "Idol" finalist Chris Daughtry, No Doubt and the debut of judge [article id="1610625"]Abdul's new single, "I'm Just Here for the Music."[/article]

Get your "Idol" fix on MTV News' [article id="1486475"]"American Idol" page[/article], where you'll find all the latest news, interviews and opinions.