Why Adam Lambert, David Cook Skipped Idol Finale

 Angela Weiss/Getty Images; Brian To/FilmMagic

About 50 former American Idol winners and contestants paid tribute to Simon Cowell on Wednesday night's finale.

But two former stand-outs were missing: season 8 runner-up Adam Lambert and season 7's David Cook, the only winner who wasn't there.

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Lambert, 28, announced on Twitter that he wasn't invited after blogs incorrectly reported he blew off rehearsals.

"HAHA. I have now just been made aware of more gossip and rumor mill: First of all, i was never asked to appear on the finale in any capacity," he said. "All i ever heard was:"you've not been asked to perform on finale.Would you like to sit in the audience?" Me:sorry-Too much work to do today."

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He's busy preparing for his first tour.

"Would have loved 2 have been at the Idol Finale to wish Simon farewell and support the finalists, but this tour for my fans is my priority," Lambert added. "was put on vocal rest yesterday from MY show's rehearsals which doubled the work 2 do 2day since all equip. had 2 be sent back east tonight."

Cook, 27, was at a charity event in his hometown of Kansas City. (He has been active in raising funds for cancer research after his brother died of brain cancer in May 2009.)

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"Congrats to Lee DeWyze! So sorry I could be there to see all my fellow idols. I'm there in spirit!" he wrote on Twitter.

Season 5's Chris Daughtry was also absent, but Twittered that he was performing in Kansas City.

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