Castro, 20, of Rockwall, TX, laughed his way through his final performance as the competition was narrowed to three: David Cook, David Archuleta and Syesha Mercado. During Tuesday's performance show, Rockwall forgot the lyrics to Bob Dylan's "Mr. Tambourine Man."

"I'd pack your suitcase," Judge Simon Cowell told Castro after "Mr. Tambourine Man."

His rendition of Bob Marley's "I Shot the Sheriff" didn't exactly get high marks, either.

"For me, that was really karaoke," Judge Randy Jackson said. "Dude, it was just OK. There was nothing special about it."

This week's theme, "500 Songs that Shaped Rock 'n' Roll," saw Cook performing Duran Duran's "Hungry Like the Wolf" and The Who's "Baba O'Riley"; Archuleta singing "Stand By Me" by Ben E. King and Elvis Presley's "Love Me Tender"; and Mercado belting Tina Turner's "Proud Mary" and Sam Cooke's "A Change is Gonna Come."

Cook, a frontrunner in the competition, received mediocre marks for "Hungry Like the Wolf" but rebounded with "Baba O'Riley."

Mercado cried after Jackson said he didn't care for the arrangement of Cooke's hit. "Sam Cooke is one of the greatest singers in life. It felt all disconnected to me. It was trying to be something it wasn't. It fell flat."

Once again, Archuleta won over the judges with his song choices. Jackson dubbed "Stand By Me" "hot, mad vocals." Judge Paula Abdul praised Archuleta for taking the judge's criticism and correcting his mistakes.

"You're taking in everything that we're saying," Abdul said. "You're seasoned already."

Cowell, however, didn't care for "Stand By Me."

"You could have whistled a song and it would have sounded better than [that]."

The results show featured performances by Maroon 5 and Bo Bice.