Watch Taylor Swift's Surprise 'Voice' Appearance

Tonight, the Top 6 take to The Voice stage and ETonline scored an adorable sneak peek at Team Usher's rehearsal!

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For her make-it-or-break-it performance, Michelle Chamuel chose I Knew You Were Trouble by Taylor Swift, and to help make the performance really soar, Usher called on a special guest mentor: Miss. 22 herself!

But, Michelle doesn't know who -- or what -- is about to walk in, and her reaction is priceless!

The Voice airs tonight and tomorrow at 8 p.m. on NBC.