7 Gibbon Song and Human Music from anEvolutionary Perspective

Gibbons (Hylobates spp.) produce loud and long song bouts that are mostly exhibited by mated pairs. Typically, mates combine their partly sex-specific repertoire in relatively rigid, precisely timed, and complex vocal interactions to produce well-patterned duets. A cross-species comparison reveals that singing behavior evolved several times independently in the order of primates. Most likely, loud calls were the substrate from which singing evolved in each line. Structural and behavioral similarities suggest that, of all vocalizations produced by nonhuman primates, loud calls of Old World monkeys and apes are the most likely candidates for models of a precursor of human singing and, thus, human music. Sad the calls of the gibbons at the three gorges of Pa-tung; After three calls in the night, tears wet the [traveler's] dress. (Chinese song, 4th century, cited in Van Gulik 1967, p. 46). Of the gibbons or lesser apes, Owen (1868) wrote: “... they alone, of brute Mammals, may be said to sing.” Although a few other mammals are known to produce songlike vocalizations, gibbons are among the few mammals whose vocalizations elicit an emotional response from human listeners, as documented in the epigraph. The interesting questions, when comparing gibbon and human singing, are: do similarities between gibbon and human singing help us to reconstruct the evolution of human music (especially singing)? and are these similarities pure coincidence, analogous features developed through convergent evolution under similar selective pressures, or the result of evolution from common ancestral characteristics? To my knowledge, these questions have never been seriously assessed. Gibbons and Their Songs