Adam Lambert's 'Glee' Debut Is (Finally) Upon Us

Adam Lambert on Glee 2 L

The wait is over for Adam Lambert fans as the American Idol alum makes his Glee debut Thursday night.

Lambert, who guest stars as Elliott "Starchild" Gilbert in the episode titled "A Katy or a Gaga," will show off his vocal chops with a version of Lady Gaga's "Marry the Night." He delivers the song during an audition to be a part of Kurt's (Chris Colfer) new band.

The season eight runner-up tells The Hollywood Reporter that's he's ready for his close-up.

"I had such a blast filming the show, and loved getting back into acting and working with such great people," he says. "I'm so excited for everyone to see it!"

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In a video promoting his appearance, Lambert reveals his character's background. “It’s an homage to [David Bowie's] Ziggy Stardust and the Spiders From Mars," he explains. "I think that he’s actually quite normal and down to earth; he goes to NYU and I think he’s kind of a theater geek."

Co-star and X Factor judge Demi Lovato has nothing but praise for Lambert, saying in the clip that his voice is "amazing," "unique" and "something you don't see very often."

In a stroke of irony, Lambert reveals that he auditioned for Glee pre-Idol, but was rejected.

"The casting director was like, 'Wow, I love your voice, but I think you're too old to be on the show,'" he said. "So I didn't get it."

In other Lambert news, the Idol favorite is currently in the studio working on his third album. Now a free agent since parting ways with RCA Records and 19 Recordings, a new record deal is also imminent especially considering recent high-profile appearances like the Avicii song "Lay Me Down," on which Lambert takes the lead vocal and a co-writing credit.

Listen to Lambert's rendition of "Marry the Night" and watch the video interview, both below. Glee airs Thursdays at 9 p.m. on Fox.

Twitter: @MicheleAmabile