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When Taylor Swift does Halloween -- she DOES Halloween. So, of course, her "1989 Tour" stop in Tampa on Halloween (which also happened to be her last stop on tour in the U.S.) was EPIC. Taylor brought out Idina Menzel to sing "Let It Go" from Frozen ... dressed as the movie's lovable snowman Olaf, and Elsa. Guess who was who?

Taylor posted several photos and videos from the show in her Olaf costume, and Idina in her Elsa costume. She wrote, "Frozen totally happened tonight. And 55,000 people sang 'Let it Go' so loudly, it nearly took my breath away. Good times, @idinamenzel ☃"

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Taylor and Idina's performance also included a quick costume change, as surrounding reindeer helped them both out of costume and into some more "1989 Tour" appropriate attire.

And the fun didn't stop there, Tay also sang "Style" in full Olaf mode. You've never seen that snowman look so good.

Happy Halloween!

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Olaf vibes.

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After the costume change, while the crowd was singing.. Taking it all in with @idinamenzel

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