Taylor Swift, Idina Menzel sing 'Frozen' song 'Let It Go' on 1989 tour

Taylor Swift invited Broadway luminary Idina Menzel to share the stage with her in Tampa, Florida, on Halloween night, as the two led a sellout crowd in "Let It Go," Menzel's signature tune from Disney's animated "Frozen."

Emerging in a costume, dressed as the movie's snowman, Olaf, Swift stood amid a dozen dancers costumed as reindeer, said the Tampa Bay Times, and told the crowd of nearly 57,000 at the Raymond James Stadium, "It feels like there's only one thing missing from that whole equation. I just wish Idina Menzel was here, dressed as Elsa, to sing 'Let It Go.' " Then after a dramatic pause she added, "It's a good thing she is, Tampa!"

A video clip on each of the stars' Instagram pages shows the Syosset-raised Menzel, 44, dressed as the film's Elsa in a sparkling aquamarine gown and belting out the tune with the 25-year-old Swift.

"Thank you, Taylor Swift!" Menzel captioned the Instagram video. "That was definitely an out of body experience. Or out of Elsa's body experience!"

Sometime afterward Swift posted a still image of the two on Instagram, writing, " 'Frozen' totally happened tonight. And 55,000 people sang 'Let it Go' so loudly, it nearly took my breath away. Good times, Idina Menzel."

Tony Award-winner Menzel is one of many surprise guests who joined Swift onstage on her 1989 World Tour, which concluded its U.S. leg with the Florida show. Among others are Mick Jagger, Steven Tyler, John Legend, Wiz Khalifa, Nelly, Pitbull, Keith Urban, Miranda Lambert, Ricky Martin and Lisa Kudrow as her "Friends" character Phoebe Buffay, duetting on Phoebe's signature tune, "Smelly Cat."