songs through such arduous study that the idea of animal conservatories with “properly qualified professors” to refine animals’ musical abilities was floated at the turn of the century.31 Though not a mark of reason, song in animals seemed very similar to song in humans. As a result, music occupied an undefined—and potentially contested—territory between animal expression and human linguistic rationality. For evolutionists like Darwin and Spencer, defining this ambiguous territory would mean defining what it meant to be human.
Darwin’s The Descent of Man, and Selection in Relation to Sex, published in 1871, used music and aesthetics to challenge prevailing beliefs about this boundary line between humans and other animals. “The place of song in the life of the bird has since the days of Darwin been a question of dispute between the scientists,” wrote ornithologist Chauncey Hawkins in 1918.32 This “dispute” echoed the broader anxieties about human uniqueness that had surrounded the Origin of Species, but focused on a new question: whether culture, instead of biology, was what set humans apart from the animals. One of the most controversial implications of the Descent was that it did not.
Darwin’s Origin of Species from 1859 had located biological history in a process of natural selection that depended on a species’ successful reproduction. In the Descent, Darwin argued that aesthetics had their origins not in divine providence but in a special kind of selection called “sexual selection,” in which animals chose their mates. Darwin spent nearly a quarter of the Descent on birds and sexual selection, displacing primates in a surprise move that voted with ink in favor of music’s role in human development. He suggested that human aesthetics descended directly from the selective processes that occurred when animals had the power to choose their own mates, arguing that generations of attracting, being chosen, and having offspring had bred a sense and appreciation of beauty in certain animals. For Darwin, these animals had the same capacity for musicality as humans. The British naturalist lauded the musical abilities of spiders, frogs, tortoises, alligators, gibbons, dogs, seals, and even Lockwood’s mouse Hespie, returning throughout his text to the question of music’s origins.33 Passion, love, breeding, persuasion, and social power all had a place in this unusual narrative of humanity’s link to animals through a process that looked very much like free will. “The impassioned orator, bard, or musician, when with his varied tones and cadences he excites the strongest emotions in his hearers, little suspects that he uses the same means by which his half-human ancestors long ago aroused each others’ ardent passions during their courtship and rivalry.”34 Darwin’s theory was popularized by figures ranging from the fictional Holmes to psychologists such as James Sully and Edmund Gurney, and musicologists such as Jules Combarieau and Robert Lach, gaining a considerable number of adherents by the early twentieth century.35
But sexual selection was a very different story from the cold and random chance of natural selection. Many intellectuals, however respectful of Darwinian evolution, were troubled by the theory that aesthetics’ origins lay in the loves, choices, and passions of animals. For many, it was simply too difficult to reconcile the impersonal forces of nature that dominated evolutionary theory with the personal, fickle individuals creating emotions that led to choosing a mate whose offspring would then choose future generations. The first-ever book on birdsong’s evolution, Charles Witchell’s The Evolution of Bird-Song, with Observances on the Influence of Heredity and Imitation of 1896, devoted almost all of its opening chapter to a critique of Darwin’s theory of musical evolution, concluding that despite certain compelling features of sexual selection, the songs of birds could not “reasonably be considered to be directly occasioned by the emotion of love.”36 The biologist Alfred Russel Wallace, who had independently engineered his own natural selection theory, argued that Darwinian sexual selection in which animals seemed to “consciously” choose their future was wrong, and should be replaced with natural selection.37 Wallace’s colleague August Weismann agreed, writing that “the musical sense is not a result of sexual selection,” and arguing instead for a nineteenth-century version of Steven Pinker’s description of music as deliciously unnecessary “auditory cheesecake”—a delightful coincidence of acoustic development useless in survival terms.38
Darwin’s most visible opponent on the matter of musical evolution was his contemporary Herbert Spencer. Spencer, a British social and political philosopher, had been a public advocate for Darwinian natural selection. Both Darwin and Spencer thought music might offer new ways to understand human differences. But while Darwin’s work was rooted in theories of biological reproduction, Spencer’s approach was framed by sociology. His writings about music, which located aesthetics in human social life rather than biological history, became the public foil for Darwin’s thinking on aesthetics, with “Mr. Darwin’s and Mr. Herbert Spencer’s” theories becoming polar twins in the discourse of music’s origins.39
The first of Spencer’s texts on music actually predated the Descent, becoming newly relevant after Darwin’s controversial book was published. Written in 1857, two years before the publication of On the Origin of Species, Spencer’s “The Origin and Function of Music” put forward an argument very similar to Herder’s from the previous century, treating music as the emotional component of early language. Spencer approached all animal sounds as exclamations or “impassioned utterances” caused by restless emotional energy. Birdsong was, in his view, functionally equivalent to barking dogs, purring cats, roaring lions, and any other shrieks and moans of pain, joy, or suffering.40 Human vocalizations, on the other hand, were uniquely rational, developing into speech, chant, and song. The evolution of these utterances could be explained as a side effect of environmental pressures and local competition, but had nothing to do with choice, aesthetics, or, especially, sexual reproduction. Spencer’s take on music was fundamentally a sociological one, connecting aesthetics to prevailing beliefs about reason, language, and the emotions. It was about human experience, not biological history; Spencer’s theory was entirely disinterested in the development of the syrinxes, tongues, mouths, and ears that accompanied song.
Darwin had briefly referenced Spencer’s essay in the Descent, but he provided a more vigorous response in The Expression of the Emotions in Man and Animals (1872). Though respectful of Spencer’s general ideas, Darwin argued that in treating all animal sounds as the same type of sound, Spencer and those like him had essentially missed the point. Spencer’s pig uttered generic exclamatory grunts; Darwin’s pig uttered a special “deep grunt of satisfaction … when pleased with its food, [that] is widely different from its harsh scream of pain or terror.”41 The barking dog that opened Spencer’s essay had yet another way of making sounds: “But with the dog … the bark of anger and that of joy are sounds which by no means stand in opposition to each other; and so it is in some cases.”42 Spencer and other advocates of the natural-selection approach to music, Darwin implied, simply failed to recognize musicality as a distinct mode of sound production, thereby failing to recognize what everybody else knew: “that animals utter musical notes is familiar to every one, as we may hear daily in the singing of birds.”43 Psychologist Edmund Gurney’s The Power of Sound (1880) added further rankle to Darwin’s criticisms, claiming a Darwinian approach was “directly opposed” to Spencer’s theories.44 Gurney even parodied Spencer’s idea that melody originated in speech cadences, with a mock example tracing J. S. Bach’s cantata Ein’ feste Burg ist unser Gott to pseudo-evolutionary origins in the English exclamation “Heigh-ho!”45
In response to his critics, Spencer had his essay reissued in 1890 with a special postscript responding to Darwin and Gurney. “Mr. Darwin’s observations are inadequate, and his reasonings upon them inconclusive. Swayed by his doctrine of sexual selection, he has leaned towards the view that music had its origins in the expression of amatory feeling.”46 “Mr. Gurney,” in his turn, suffered from “deficient knowledge of the laws of evolution” in his support for Darwin.47 Objecting to the suspicious developmental gap between birds and primates in Darwin’s explanation, Spencer attacked the idea of birdsong as a courtship ritual, calling it “untenable” and
