Choralis, founded by Artistic Director Gretchen Kuhrmann, is a 100-person mixed-voice chorus now celebrating its 12th season. Sunday, September 11 at 4:00 pm, they present In Search of Peace: A Concert of Remembrance and Hope for the 10th Anniversary of 9/11 at the National Presbyterian Church. The concert features the world premiere of a work Choralis commissioned from composer Gary Davison for this event called "Shadow Tides." Also on the program is Samuel Barber's Adagio for Strings, music from Morten Lauridsen's Lux Aeterna, and the Dona Nobis Pacem from JS Bach's B-minor Mass. Classical WETA's Deb Lamberton spoke with Choralis Artistic Director Gretchen Kuhrmann about the choir, and Sunday's 9/11 commemorative concert.