<P> Zoomusicology is the study of the music of non-human animals, or the musical aspects of sounds produced by non-human animals . As George Herzog (1941) asked, "do animals have music?" François - Bernard Mâche's Musique, mythe, nature, ou les Dauphins d'Arion (1983), a study of "ornitho - musicology" using a technique of Nicolas Ruwet's Langage, musique, poésie (1972) paradigmatic segmentation analysis, shows that bird songs are organised according to a repetition - transformation principle . Jean - Jacques Nattiez (1990), argues that "in the last analysis, it is a human being who decides what is and is not musical, even when the sound is not of human origin . If we acknowledge that sound is not organised and conceptualised (that is, made to form music) merely by its producer, but by the mind that perceives it, then music is uniquely human ." </P> <P> In the West, much of the history of music that is taught deals with the Western civilization's art music, which is known as classical music . The history of music in non-Western cultures ("world music" or the field of "ethnomusicology"), which typically covers music from Africa and Asia is also taught in Western universities . This includes the documented classical traditions of Asian countries outside the influence of Western Europe, as well as the folk or indigenous music of various other cultures . Popular or folk styles of music in non-Western countries varied widely from culture to culture, and from period to period . Different cultures emphasised different instruments, techniques, singing styles and uses for music . Music has been used for entertainment, ceremonies, rituals, religious purposes and for practical and artistic communication . Non-Western music has also been used for propaganda purposes, as was the case with Chinese opera during the Cultural Revolution . </P> <P> There is a host of music classifications for non-Western music, many of which are caught up in the argument over the definition of music . Among the largest of these is the division between classical music (or "art" music), and popular music (or commercial music--including non-Western styles of rock, country, and pop music - related styles). Some genres do not fit neatly into one of these "big two" classifications, (such as folk music, world music, or jazz - related music). </P> <P> As world cultures have come into greater global contact, their indigenous musical styles have often merged with other styles, which produces new styles . For example, the United States bluegrass style contains elements from Anglo - Irish, Scottish, Irish, German and African instrumental and vocal traditions, which were able to fuse in the United States' multi-ethnic "melting pot" society . Some types of world music contain a mixture of non-Western indigenous styles with Western pop music elements . Genres of music are determined as much by tradition and presentation as by the actual music . Some works, like George Gershwin's Rhapsody in Blue, are claimed by both jazz and classical music, while Gershwin's Porgy and Bess and Leonard Bernstein's West Side Story are claimed by both opera and the Broadway musical tradition . Many current music festivals for non-Western music include bands and singers from a particular musical genre, such as world music . </P>

Which of the following elements of music has to do with time relationships