Simultaneously, Helmholtz began developing his theories of resonance, leading to understandings of pitch, frequency, and timbre that drew explicitly on racialized ideas of musical sound. According to historian of science David Pantalony, “Musical culture was central to German science in the nineteenth century; it inspired inquiry, formed social cohesion and stimulated collaboration between scientists, musicians, and instrument makers,” and Helmholtz was an “exemplar” of musical influence.14 As I discuss in chapter 2, distinctions between forms of European music took on racial overtones in addition to national ones, with Italian music’s so-called overly emotional and gestural sonics taking on qualities the sonic color line associated with blackness, particularly irrationality; white Americans increasingly racialized classical music as “white” during the 1850s in the quest to distinguish a distinctly American popular culture, particularly through the visit of white Swedish opera singer Jenny Lind and the Northern tour of black American opera singer Elizabeth Taylor Greenfield. New avenues of acoustic experimentation did not just explain musical phenomena but rather flowed from musical training and its influence on nineteenth-century thought. Veit Erlmann notes that Helmholtz “frequently and early on in his career used hearing and music to elaborate key aspects of his theory of knowledge.”15 Unfortunately, there is little existent research on the relationship between nineteenth-century racial science and the growing field of acoustics. However, the rise of the sonic color line alongside the Western scientific “reform of acoustics” suggests that racial science did not need to say anything directly about racial categorization of vocal tone if the very impetus to name and explore the notion of timbre arose from the influence of racially classified music as well as the hyperclassification of difference. The piano, for example, was Helmholtz’s conceptual model for the inner ear, where every one of Corti’s newly discovered hairs individually corresponded to specific frequencies and would vibrate when struck, just like a piano wire. Helmholtz’s theory allowed for the separation of sounds in the ear, even if they are perceived simultaneously. Timbre, the notion that sounds have a peculiar, difficult-to-identify quality that distinguishes the musical tone between instruments producing the same note at the same pitch, then also enables a key tenet of the sonic color line—that men and women of different races have essentially different and discernable vocal tones. Helmholtz’s idea regarding separated receptors for various timbres further extends the sonic color line into the realm of the biological, suggesting that listening operates through a hardwired physical form of sonic segregation.
Thus strengthened, however indirectly, through racial science, the sonic color line enabled white elites to tighten slavery’s strictures as rising protest destabilized the institution. Mark M. Smith contends that many whites began to question the dominance of sight in racial discourse in the 1850s, after generations of sexual predation by slave masters gave rise to increasing numbers of “visually white slaves.” Fears of being unable to reliably see “blackness” in the “one drop rule” society they had set up led white Southerners to construct essential racial difference beyond the visual.16 Furthermore, as Spillers argues, “it is, perhaps, not by chance that the laws regarding slavery appear to crystallize in the precise moment when agitation against the arrangement becomes articulate in certain European and New World communities.”17 Most obviously, the fight over slavery in America’s newly conquered Western territory polarized the country and heightened what Smith dubs “aural sectionalism” between abolitionists and slaveholders. However, even though “Northerners and Southerners heard one another in profoundly and emotionally divisive ways,”18 they increasingly developed similar listening practices when it came to race. For example, implementing the Fugitive Slave Act in 1850, which demanded all escaped slaves be returned to their masters wherever captured, accelerated the sonic color line’s development and extended its reach to the Northern states. On penalty of fines up to 1,000 dollars and six months’ imprisonment, every white Northern citizen was legally mandated to report fugitives to the authorities, “after notice or knowledge of the fact that such person was a fugitive.”19 Because “there was not much that could be done to identify such slaves by sight alone,” other socially constructed sensory indicators of racial identity became salient, especially culturally identified aural markers of slavery such as “slow speech, accent, dialect, stuttering.”20 These aural markers located slavery within the fugitive body rather than in the institution that produced and conditioned such differences.
Alongside scientific pronouncements and legal compulsions, the ideological foundations of nineteenth-century oratory culture helped define and spread the sonic color line, further stressing the relationship between aurality and rationality. Douglass felt the tension between the two all too well; his narrative is rife with references to Caleb Bingham’s 1797 primer The Columbian Orator, a popular text that helped define American social standards for sound in the arena of public speaking and beyond. Douglass first purchased the Orator at age twelve, after illicitly learning to read. While largely a collection of famous speeches, the Orator opens with “General Instructions on Speaking,” an essay providing theoretical and practical pointers to aspiring orators. Confirming the rationale behind abolitionists’ use of sound as emotional appeal while discouraging its unseemly deployment, Bingham’s rules claim that “the influence of sounds, either to raise or allay our passions is evident from music. And certainly the harmony of a fine discourse, well and gracefully pronounced, is as capable of moving us, if not in a way so violent and ecstatic, yet not less powerful, and more agreeable to our rational faculties.”21 By declaring the “influence of sounds” separable from their meaning as “fine discourse,” the Orator firmly knits aurality to “passion” rather than the “rational faculties.” Bingham also expresses an idea key to the formation of the sonic color line and the listening ear, that music and speech are fluid parts of an increasingly organized theory of sounding in which various aural technologies work together to produce the controlled “harmony” of rationality. In attuning the evolving listening ear to recognize and seek out “harmony” in both music and speech, Bingham classified any “violent, “ecstatic,” and excessively emotional sounds as threats to the social order.
Championing the sound of restraint, a cultural construct the post-Enlightenment mind-body split associated with whiteness and intellect, the Orator harmonizes a modulated “clear” sound with verbal clarity. Because sound can rather unpredictably “raise or allay” emotion, it necessitated a grammar that quelled its potential for excess, aligning it with white bourgeois ideals of “harmony,” itself a culturally specific sonic symbol of order, a musical “conciliator of sounds.”22 Bingham’s use of “ecstatic” is especially telling; its etymology stems from a Greek root meaning “to put out of place,” connoting sound’s ability to unseat rationality.23 It also alludes to the sonic color line, as antebellum whites often used “ecstatic” to describe what they considered the irrationality and excess of black speech, music, and worship.24 Bingham pronounced “a calm and sedate voice is generally best; as a moderate sound is more