Photo Flash: TO KILL A MOCKINGBIRD Rehearses For Madison Square Garden Performance

Tonight, the Broadway production of To Kill A Mockingbird, Aaron Sorkin's new play, directed by Bartlett Sher, and based on Harper Lee's classic novel, will become the first-ever Broadway play to perform at New York's Madison Square Garden.

This unprecedented, single-performance event will be entirely free to approximately 18,000 students of New York City Department of Education public middle and high schools from all five boroughs.

Check out photos from yesterday's rehearsal below!

This special performance of To Kill A Mockingbird will feature the entire Broadway cast, led by four-time Academy Award nominee and two-time Golden Globe Award winner Ed Harris as Atticus Finch.

It was also confirmed that New York City Mayor Bill de Blasio, First Lady Chirlane McCray, and filmmaker (and New York Knicks fanatic) Spike Lee will introduce the afternoon. Mayor de Blasio will also declare tomorrow as "To Kill a Mockingbird Day" in New York City.

Set in Alabama in 1934, Harper Lee's enduring story of racial injustice and childhood innocence centers on one of the most venerated characters in American literature, the small-town lawyer Atticus Finch, played four-time Academy Award® nominee and two-time Golden Globe Award® winner Ed Harris. Joining Mr. Harris are Nick Robinson as Jem Finch, Eliza Scanlen as Mayella Ewell, Kyle Scatliffe as Tom Robinson, LisaGay Hamilton as Calpurnia, Nina Grollman as Scout Finch, Taylor Trensch as Dill Harris, Manoel Felciano as Horace Gilmer, Russell Harvard as Link Deas and Boo Radley, Dakin Matthews as Judge Taylor, Patricia Conolly as Mrs. Dubose, Christopher Innvar as Sheriff Heck Tate, William Youmans as Mr. Roscoe and Dr. Reynolds, Neal Huff as Bob Ewell, Ted Koch as Mr. Cunningham, Liv Rooth as Ms. Stephanie, and ensemble members Rosalyn Coleman, Gene Gillette, Luke Smith, Yaegel T. Welch, Rebecca Watson, Aubie Merrylees, David Manis, Baize Buzan, Steven Lee Johnson, and Geoffrey Allen Murphy.