Katharine McPhee 'Smash-es' Into 'The Voice' (Video)

The "American Idol" alum drops by the NBC show and delivers some music news.

 Ruh roh, is Katharine McPhee crossing to the enemy’s side? The American Idol Season 5 runner-up dropped by Idol's rival singing competition The Voice on Tuesday to talk about her new series, Smash, plus she announced she would be doing her own version of one of the coaches' hits.

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It’s never too early to get some promotion out there – especially with 12 million viewers tuned in. McPhee talked up NBC’s new musical drama, which she’s costarring in with Will & Grace’s Debra Messing and FlashForward’s Jack Davenport. The series will be the lead in to The Voice on Mondays this winter.

She also talked about doing her own version of Christina Aguilera’s “Beautiful” on her new show, which the coach performed with her team’s finalist, Beverly McClellan, on Tuesday’s show. Now, that’s synergy.

Watch Aguilera and McClellan's duet on "Beautiful" below.