A showy musical theatre actor and his clean-cut acoustic guitar-playing rival get their last chance to woo viewers and votes on Tuesday night in the final performance episode of "American Idol."

After 100,000 people auditioned last summer and five months of broadcasts on the Fox network, Adam Lambert, 27, and Kris Allen, 23, are expected to sing three songs each before "Idol" viewers call in their votes to anoint the eighth winner of the TV ratings juggernaut. The winner will be announced at the season finale on Wednesday night.

The Lambert-Allen matchup marks the third time in "American Idol" history -- and the second year in a row -- that the show's finale has come down to two male contestants. The two finalists reportedly roomed together for much of the season at the so-called Idol Mansion, apparently because they both have a penchant for neatness.

That's about all this year's two finalists have in common, however.

Widely considered the front-runner going into the finale, the flamboyant, nail-polish-wearing Lambert has wowed audiences with his off-the-charts vocal range, outrageous costumes and his willingness to take risks with songs like Johnny Cash's "Ring of Fire" and Led Zeppelin's "Whole Lotta Love."

"From a pure TV spectacle standpoint, this is the Adam Lambert show," said Michael Slezak, who covers "American Idol" for Entertainment Weekly. "It's hard to deny his effect and his dominance."

Nicknamed "Glambert" by his fans, the San Diego native was in the cast of the Los Angeles production of the musical "Wicked" before auditioning for "Idol."


At the other end of the spectrum, Allen is a laid back Arkansas student who most often performs with his acoustic guitar or at the piano. Like Lambert, however, he has won praise for putting his own spin on tunes, among them Bill Withers' "Ain't No Sunshine" and Michael Jackson's "Remember the Time."

As recently as last week, the recently wed Allen was considered a long shot heading into the battle for the top two "Idol" spots, but wowed the show's judges with his rendition of Kanye West's "Heartless," ousting early favourite Danny Gokey.

"Idol" watcher Slezak, however, cautioned against assuming that a Lambert victory was a foregone conclusion, saying Allen seems well-placed to succeed in the music business beyond "American Idol."

"In terms of artists who are going to create records that are going to sell, he's neck and neck with Adam Lambert," Slezak said. "People like to say that he is the weaker vocalist, but we haven't really heard many bum notes from Kris Allen this season. This guy's pretty good."

"American Idol" has been America's most-watched TV show for several years, attracting an average audience this year of more than 26 million viewers per episode. It has produced bona fide music stars including country singer Carrie Underwood, Grammy winner Kelly Clarkson, rocker Chris Daughtry and Oscar-winner Jennifer Hudson.

(Reporting by Nichola Groom; Editing by Jill Serjeant and Eric Beech)