Producers added the special performance to thank fans who have waited outside the theatre on a daily basis in the hopes of winning The Book of Mormon ticket lottery.
According to producers, up to 300-400 people have lined up at each performance to enter the ticket lottery. Anyone who had entered his or her name into the lottery, or checked in on Foursquare, was automatically entered to win tickets for the July 1 matinee. Winners were notified in mid-June.
Here's a look at the crowds lining 49th Street and a glimpse of the actors arriving at the theatre.
Fans Line Up For Free Book of Mormon Performance
"South Park" creators-writers Trey Parker and Matt Stone, and Tony-winning Avenue Q songwriter Robert Lopez collaborated on the script and score to the musical, which earned Tony Awards for Best Book, Best Score and Best Musical.
The Book of Mormon also picked up Tony Awards for Best Direction (Parker and co-director/choreographer Casey Nicholaw), Best Performance by a Featured Actress (Nikki M. James), Best Orchestrations (Larry Hochman and Stephen Oremus), Best Scenic Design (Scott Pask), Best Sound Design (Brian Ronan) and Best Lighting Design (Brian MacDevitt).
Josh Gad ("The Daily Show with Jon Stewart") and Andrew Rannells (Jersey Boys) star as an unlikely pair of Mormon missionaries who venture from Salt Lake City to AIDS-ravaged Uganda in the hopes of converting villagers with the story of Joseph Smith and the founding of the Mormon Church. The problem is: Only one of them has actually read the book.
The cast also features Rory O'Malley (The 25th Annual Putnam County Spelling Bee) as Elder McKinley, Tony winner James (All Shook Up) as Nabalungi and Michael Potts (Grey Gardens) as Mafala Hatimbi, as well as Lewis Cleale, Scott Barnhardt, Justin Bohon, Darlesia Cearcy, Kevin Duda, Asmeret Ghebremichael, Brian Tyree Henry, Clark Johnsen, John Eric Parker, Jason Michael Snow, Benjamin Schrader, Michael James Scott, Brian Sears, Lawrence Stallings, Rema Webb, Maia Nkenge Wilson, Tommar Wilson, Graham Bowen, Ta’Rea Campbell, Jared Gertner, Tyson Jennette and Nick Spangler.
Parker and Stone have earned four Emmy Awards and a Peabody Award for "South Park," which is now in its 15th season. Their films include "South Park: Bigger, Longer and Uncut" (Academy Award nomination for Best Song) and "Team America: World Police."
Lopez co-created Avenue Q, earning 2004 Tony Awards for Best Musical, Best Score and a Grammy Award nomination for Best Cast Album. He has also penned Finding Nemo: The Musical with his wife Kristen Anderson-Lopez.