One of the heroes of Public Acoustics is Claude Perrault—a fascinating figure who should be better known outside of early modern French studies circles. Readers are more likely to have heard of his brother Charles who published influential versions of classic fairy tales such as "Little Red Riding Hood." To my mind, Claude is the more interesting of the brothers. A true polymath, he was a physician, an architect (helping design the east façade of the Louvre), a natural historian who conducted public dissections of exotic animals in Paris, and a music lover. Claude's scientific and artistic sides came together in his work on sound. He wrote a treatise on the physics of sound, titled Du bruit or About Noise. He also wrote an essay about music, which is in part a defense of complex, richly textured compositions at a time when a taste for simpler, homophonic musical styles was becoming more dominant.

In my book, I discuss an unpublished preface to this essay in which Perrault considers the social, political, and ethical implications of musical taste. It tells a story about an evening he spent at the opera to hear a work by Robert Cambert and Gabriel Gilbert. It's important to know that the opera was a key social space in late seventeenth- and eighteenth-century Paris. Its audiences were famously talkative and boisterous, such that the opera public came to stand for the idea of the Parisian public itself. This association is present in Perrault's text. He describes listening to the chatty, restive audience while waiting for the opera performance to begin. Amid the general hubbub, he eventually discerns an interesting debate taking place between two music connoisseurs, one who prefers the clarity of classical composition styles and another who favors more complex "assemblages of voices and instruments" produced by contrapuntal musical forms. This second connoisseur wins the argument, helped in no small part by the start of the opera and its multipart choral prologue which overwhelms his opponent with its sonic beauty.

In his longer essay, Perrault praises counterpoint composition not only on its aesthetic merits but also for the habits of listening it can encourage. A "fine ear," he argues, takes pleasure in this kind of music specifically because it requires a cognitive effort to "untangle" different melodic lines and appreciate the "pleasing diversity" of voices. He describes a kind of virtuous circle whereby listening to multipart music refines the ear, and the more skilled listener is more apt to appreciate complex compositions.

Indeed, throughout his work on sound and music, Perrault rejects dichotomies of good versus bad sound, reframing distinctions in terms of simple and complex. In Perrault's time as today, many of us think about "sound" as a neutral category and "noise" as annoying, grating, or unwanted sound. In Du bruit, Perrault proposes that "sound" indicates single, pure tones whereas "noise" is the broader term, capturing the full range of what the ear can perceive. Noise isn't annoying or unlistenable. Rather, it requires a different set of perceptive skills and habits to discern.

In the scene at the opera, Perrault begins to suggest that his generous approach to theorizing noise might also have applications for the way people interact and communicate. Like the capable listener who appreciates harmonic music, the narrator picks out individual voices and follows the line of their arguments. Rather than impose an artificial unity or dismiss the chatter as incomprehensible noise, he appreciates the irresolvable tensions in these debates and reflects on the "new difficulties" that continually refine the discussion. His way of listening reframes the noise of social chatter as intelligible complexity. In this way, when Perrault imagines that debate between music lovers at the opera, and the murmurs, groans, and applause of the other audience members attending to their discussion, he suggests how music connoisseurship could offer us a model for listening to the talk all around us, pointing to a way of inhabiting a social world in all its complexity. He implies that there is pleasure to be found in tuning into the many voices of society.