The 70-minute concert, which was introduced by Ted Chapin, featured Peterson and Mallory recounting their experiences as unknown actors in New York who rose to fame in the 1968 Lincoln Center revival of West Side Story (as Tony and Maria) and later appeared in the original production of Follies (as Young Ben and Young Heidi).
The pair sang songs from shows they appeared in separately and together, along with other favorites, including "You're Gonna Love Tomorrow" and "One More Kiss" from Follies, "Soon" from A Little Night Music, "Being Alive" and "The Little Things You Do Together" from Company, and "Kiss Her Now" from Dear World. The program also featured two songs written specifically for the concert by Peterson and Jesse Wiener.
When Everything Was Possible was directed by Larry Moss, with musical staging by Joshua Bergasse, musical direction by Michael Rafter, lighting by Carolyn Wong, sound design by Leon Rothenberg, and projection design by Telegraphicmedia. Tunick provided new orchestrations written specifically for the concert.