The demure 18-year-old singer from McKinney, Texas, fizzled Wednesday with her rendition of “Flashdance” by Irene Cara during an evening of 1980s tunes on the Fox talent competition. After her performance, “Idol” judge Jennifer Lopez warned Cavanagh to stop listening to everyone and “let it go” when she’s performing on stage. Steven Tyler was more blunt.

“Your pitch was all over the place,” he said. “I’m so sorry to tell you.”

The panel also wasn’t in love with Elise Testone’s take on “I Want to Know What Love Is” from Foreigner. Tyler told the rocker, who impressed with Led Zeppelin’s “Whole Lotta Love” last week, that he didn’t think it was the “right song choice,” while Randy Jackson informed the 28-year-old teacher from Charleston, S.C., that she was “much better than this.”

“It was just out of tune everywhere for me,” he said.

There was much more praise for the other finalists, including 20-year-old face painter Colton Dixon of Murfreesboro, Tenn., with Cyndi Lauper’s “Time After Time”; growly 21-year-old pawn shop worker Phillip Phillips of Leesburg, Ga., with Genesis’ “That’s All”; and 17-year-old student Deandre Brackensick of San Jose, Calif., with DeBarge’s “I Like It.”

“I like it,” Lopez told the curly haired singer. “I like it a lot.”

The judges were on their feet for a gospel-infused version of Simply Red’s “If You Don’t Know Me by Now” from 19-year-old student Joshua Ledet of Westlake, La. They were also pleased with Whitney Houston’s “How Will I Know” from 16-year-old student Jessica Sanchez of San Diego. The closing take on Bette Midler’s “Wind Beneath My Wings” from Skylar Laine incited a very different kinda of reaction: Lopez was on the verge of tears.

“I wanted to show my full range, and I hope I did tonight,” said the 18-year-old country rocker from Brandon, Miss.

Between the individual performances, the eight finalists paired up for male-female duets: Laine and Dixon waded through “Islands in the Stream” by Kenny Rogers and Dolly Parton, Brackensick and Cavanagh took on “I’m So Excited” by the Pointer Sisters, and Phillips and Testone bonded for “Stop Dragging My Heart Around” by Stevie Nicks and Tom Petty.

“I want more of that show,” Lopez cooed to Phillips and Testone.

However, it was the vocal sparring between Ledet and Sanchez on “I Knew You Were Waiting (For Me)” by Aretha Franklin and George Michael that won the most praise from the judges. Jackson claimed it was “one of the greatest performances” he’s seen on “Idol,” while Lopez not-so-subtly suggested she could see the pair going up against each other in the finale.

The remaining singer with the fewest viewer votes will face elimination Thursday.