In a chat on LIVE with Kelly and Ryan, Gyllenhaal discussed how at certain points in the show, he'll walk into the crowd.
"Sometimes it's very emotional; we laugh a lot, but there have been people who I can hear that are moved or crying, and we talk to each other," the performer said. "It's not improvisation as much as it is acknowledging that we're all in a place with no judgment, where we can all just be open to it."
The show, directed by Carrie Cracknell, is a double-bill of monologue plays (Tom Sturridge performs the first) about two fathers reflecting on their lives and relationships with their families.
Next year, Gyllenhaal is set to reunite with Tony winner Annaleigh Ashford in London for a West End production of Sunday in the Park with George, reprising their performances after a Broadway bow at the Hudson.