Just finished Alex Ross's magisterial, eminently re-readable survey of the 20th century in "classical" or "concert" music. I can't recommend it highly enough to readers with any interest in contemporary cultural life outside the stampeding hegemony of pop. The book answers a question so obvious that no one had thought to ask it, exactly: What was it about 20th-century classical music that still raises hackles on all sides? Ross's answer is twofold, I think: First, look at the 20th century itself. Was it an era of unending harmony and consonance in which Western civilization earned its ascendance? Didn't think so. Second, and just as crucial, composers didn't just react passively to the century's challenges but pursued their own willful solutions in ways that were variously technocratic, populist, escapist, and fascistic.
Among Ross's many gifts as a critic is his precision and breadth of musical knowledge; he reads the scores as well as listens, in other words, and I think he artfully balances the two approaches well enough for "lay" readers. I wonder, though, how much a non-musical reader will pick up on what seemed to me to be the book's most recurring reference: to melodic jumps and chord changes across the infamous "Devil's interval" of the tritone (think the first two notes of West Side Story's "Maria"). It's there in the first opera Ross focuses on (Strauss's Salome, with its telltale G to C# modulation), and it seems to crop up regularly whenever a composer working in even a remotely tonal realm (Shostakovich, Britten, etc.) reaches for a transfiguring sound. I didn't do a formal count of it, but the last one I saw was in a reference to Lutoslawski's bracing Third Symphony, in the book's final chapter. Forget 12-tone writing (please): I would nominate the tritone as the distinctive harmonic sound of the 20th century. As this diverting BBC article makes clear, it's now everywhere from the "Simpsons" theme to heavy metal.
Of course, there's so, so much more in Ross's meticulously evenhanded, enthralling tome, which combines erudition and elegance, circumspection and skeptical acuity--and on a series of notoriously knotty, trip-mined topics--like few writers I've ever encountered. And how cool is this?
UPDATE: From Gary Giddins' recent New Yorker piece about bossa nova:
Jobim and Gilberto belonged to a generation that had grown up with bebop. While the tunes written by bebop innovators like Charlie Parker, Dizzy Gillespie, and Bud Powell were often too volatile and complicated for contemporary listeners, Jobim found a way of using bebop harmonies—especially the tritone, or flattened fifth—as the basis for irresistibly lyrical melodies. One of his most famous songs, “Desafinado”—the title means “slightly out of tune,” or “off key”—is built almost entirely on discords.