In conjunction with the exhibition, the Library’s Music Division and Signature Theatre in Arlington, Va., will present a unique concert on Monday, Oct. 15, at 8 p.m. in the Coolidge Auditorium of the Library’s Thomas Jefferson Building. Members of the cast from Signature’s current production of “Merrily We Roll Along” will perform cut songs from “West Side Story,” early versions of songs with variant lyrics, readings from some of the papers in the Bernstein Collection and other surprises. The program will be directed by Signature Theatre’s artistic director Eric Schaeffer, with Jon Kalbfleisch as the musical director and pianist. For more information about this concert and others in the Library’s 2007–08 concert series, visit www.loc.gov/rr/perform/concert/0708-schedule.html.