In Season 5's penultimate episode, the remaining four acts perform in Hollywood for the final time.

Disparate acts are featured in continuing preliminary auditions.

Preliminary auditions continue.

The semifinal round begins with 12 acts performing in a bid to break into the Top 10.

Auditions continue.

Twelve acts from the Top 48 take the stage in the fourth week of performance showcases.

Four acts advance to the Top 24 in a results edition. Rocker Bret Michaels and British singer-songwriter Taio Cruz perform.

Twelve acts from YouTube perform in Hollywood.

Five semifinal contestants win a position in the Top 10 in a results show. Jimmy Fallon and singer Kylie Minogue perform.

The semifinal round continues with 12 acts performing.

Open auditions are held in Dallas.

Twelve acts from the Top 48 showcase their talents in the second week of performance shows.

Open auditions continue.

Contestants perform for the judges in Las Vegas in hopes of making it into the top 48.

Four winning acts are selected for the sought-after Top 24 in a results edition.

Five winning acts advance to the Top 10.

The final four acts are revealed. Sarah McLachlan sings "Forgiveness" and the cast of the stage show "American Idiot" performs.

The stress spikes when judges Sharon Osbourne, Howie Mandel and Piers Morgan deliberate over which acts to select for a spot in the Top 48.

Four acts win a slot in the Top 24 in a results show. Singer-songwriter Mike Posner and hip-hop dance troupe JabbaWockeeZ perform.

The Top 10 acts perform in Hollywood in their quest to win a sought-after position in the final four. Enrique Iglesias performs "I Like It."

The talent contest opens its fifth season with open auditions in Los Angeles.

Season 5's open auditions continue.

Preliminary auditions continue.

Four acts advance to the Top 24 in a results installment. Cirque du Soleil perform the show "Kà," and the rock band Train sing "Hey, Soul Sister."

Season 5's preliminary auditions continue.