"You'll see that I'm a double threat and not a triple threat," Groban joked in the video, before Bareilles teased that she would have 121 outfit changes during the evening.

Six-time Grammy nominee Bareilles, known for such pop hits as "Brave" and "Love Song," made her Broadway debut composing the score for Waitress and has taken on the title role of Jenna in two limited engagements. She starred as Mary Magdalene in NBC's Jesus Christ Superstar Live in Concert.

Groban has earned four Grammy nominations, including two for his showtune-infused Stages (the first in 2015 and a second the following year for the live album). In 2016, he made his Broadway debut in Natasha, Pierre & The Great Comet of 1812, taking on the title role of Pierre and earning a Tony nomination the following spring. This fall, he will embark on a U.S. tour with Idina Menzel.

“The theatre has completely transformed my life in every way possible. I have never felt more embraced and encouraged by a professional community, and I am so grateful for that,” said Bareilles in a statement. “It is my great honor to join my friend Josh Groban in hosting the Tonys this year, and use the opportunity to simply say a heartfelt ‘thank you’ to this wonderful community...in high heels, with jokes.”

Groban added, "To be at the helm of a night celebrating the best of that theatre with a person I just laugh way too much with is beyond words. But I will have words on Tony night! The best words! I look forward to flailing about in front of my peers. It will be with all the love and respect in the world for the room we're lucky enough to be in."