formation to other birds of the same species. Further, different discrete groups of brain cells in songbirds are responsible for different aspects of learning to sing and producing song, as appears to be the case in humans.(2) So there are many commonalties between birdsong and human language.
A second and last example is that of the vocalizations of our primate cousin, the gibbon. These are of sufficient complexity to warrant the term "song" without any great stretch of either the imagination or the language. Thus, the songs of male gibbons are organized "... within a framework of rules that define regular patterns in the placement and order of note types." When the meaning of such songs was determined behaviorally, it was discovered that the "... proper sequential organization of notes is required to encode the meaning of the song...".(3) Don't our songs have similar, if not identical, characteristics?
Neither example is intended to suggest that human song evolved directly from either songbirds or gibbons; neither of these taxa constitute our direct ancestors. Rather, such findings suggest that human singing is not unique and that it may be biologically based, perhaps in the sense that the hominid capacity for song may have had some selective advantage in the passing on of one's genes. This possibility aside, some workers view song as a stage in the evolution of language. Thus, Bruce Richman, writing in the journal Contemporary Anthropology, notes that many researchers categorize human vocalization into two opposed systems, expressive sounds (e.g., sighing, crying, laughing) and speech. Richman believes that a third type of vocalization lies between them -- singing. "Singing and speech seem very different; ... singing is more expressive of emotions than speech." He further holds that the social functions of singing provide something that speaking does not do. "... group singing gives ... a strong, direct feeling of social cohesion and solidarity." Finally, he proposes that singing "... served as an evolutionary transitional state between primate-like vocalizations and speech.(4)
What about human song, particularly in infants and children? The appearance and development of song in infants and children has been studied in some detail. (For very informative broad reviews of musical development see Shuter-Dyson and Gabriel, 1981 and Hargreaves, 1986).(5) During the first year of life, song babbling is evident(6) and recognizable spontaneous singing can be observed as early as six months of age.(7) Ries reported that spontaneous singing at seven months of age was quite distinctive.(8) Researchers have identified a developmental sequence. Early singing consists largely of melodic-rhythmic patterns of contour (pattern of higher and lower notes), without accuracy of pitch. Dowling reports that at approximately two years of age, songs usually consist of the repetition of a single brief melodic phrase, e.g., "Hoppy-hoppy run 'round the road". Complexity increases with age with the addition of more phrases. Recognition of the correct pitch may develop as early as the third year, although singing the correct pitch is usually not present for several years.(9)
Welch has provided a good review of the development of child song, salient features of which are quoted here.(10) After babbling, in which infants often play with "... glissandi and groups of musical pitches and phrases in a repetitive fashion ... words and fragments of song text ... become the focus of attention, followed by certain rhythmic features and, subsequently, the pitch components." The basic learning hierarchy appears to be: "Words -> Rhythm -> Pitch" This develops further: "Pitch Contour -> Individual Phrase Stability -> Overall Key Stability". "By the age of five to six years, young children's singing may have acquired many of the features of the significant adult models."
That key features of adult song are present so early does not imply that songs of young childhood are miniature adult songs. Veldhuis studied the spontaneous singing of four year olds in a free-