Molly Mason admits she didn't know much about Civil War music when she and her husband, Jay Ungar, were tapped by Ken Burns to play the haunting soundtrack for The Civil War PBS-TV series. (Ungar wrote the now-famous “Ashokan Farewell” used by Burns as the epic documentary's theme.) “We didn't watch the footage,” Mason says of the recording session for the soundtrack, “but Burns gave us emotional guidance for the music.”

After they watched the series, Mason and Ungar began to read about the Civil War, visit battle sites and, naturally, look into the music of that period. Mason's favorite source is a book called Heart Songs: Melodies of Days Gone By. Published in 1907, the book was based on a poll by a popular magazine of the day, asking readers to select their favorite songs. “The book contains light arias that people would have known, Civil War favorites and parlor songs,” she says.