A full century after Arnold Schoenberg and his students Alban Berg and Anton Webern unleashed their harsh chords on the world, modern classical music remains an unattractive proposition for many concertgoers. Last season at the New York Philharmonic, several dozen people walked out of a performance of Berg's Three Pieces for Orchestra; about the same number exited Carnegie Hall before the Vienna Philharmonic struck up Schoenberg's Variations for Orchestra. The mildest 20th-century fare can cause audible gnashing of teeth. Benjamin Britten's Serenade for Tenor, Horn and Strings is a more or less fully tonal score, yet in 2009 at Lincoln...