Terry Kinney directs the production, which also stars Callie Thorne, Frederick Weller, and Gia Crovatin.
The Oscar winner joined the cast onstage to sing a special encore finale.
I mean, we're not complaining.
Rannells will join the Tony-winning revival on August 20.
The trophy traveled to Manhattan as part of its press tour.
Check out the stars before they take the stage at the supper club.
Stiles stars in the Cherry Lane Theatre production along with James Wirt.
Check out the stars as they got ready to perform the one-night-only concert for The Transport Group.
Scott Organ's romantic comedy plays the Cherry Lane Theatre.