But consider the fact that, as Ortony, Clore, and Collins, in The Cognitive Structure of Emotions, argue, the emotions have a structure similar to language (and to music):
there are three major aspects of the world, or changes in the world, upon which one can focus, namely, events, agents, or objects. When one focuses on events one does so because one is interested in their consequences, when one focuses on agents, one does so because of their actions, and when one focuses on objects, one in interested in certain aspects of imputed properties of them qua objects. (18)
Subject-action/verb-object. The structure of grammar and of narrative. If there is a message, that means there is an intended audience. Music (as well as song and storytelling) in its creation has subject-action-object/receiver structure. More than this, "several behavioral features in listening to music are closely related to attachment: lullabies are song to infants to increase their attachment to a parent, and singing or playing music together is based on teamwork and may add group cohesion." So there is a social element to music-making, singing, and storytelling. Prior to writing, epic storytelling involved the storyteller's response to the reactions of the audience. If the audience showed boredom, increase action; if the audience showed they didn't like the story, shift to a different subplot. In addition, it seems that listening to music helps one with determining the emotional state of others -- something of definite adaptive advantage for a social species.
Chimpanzees and bonobos are generally quiet (bonobos less so than chimpanzees) in the wild. Some of their communication is vocal, but most is facial and gestural (visual). Gibbons, however, sing. Gibbons are members of the “lesser apes,” and move through the trees using brachiation – they swing through the trees using their arms. This gives them and orangutans both more upright stances, since their legs hang down under their bodies as they swing. To attract mates and maintain social bonds, gibbons sing. So it would not be too much of a stretch to suggest the ancestor of humans could have been a singing ape too. Especially once our ancestors became bipedal, and our larynx dropped and stretched out, giving them a wider range of sounds. This would suggest that music could have been a primary precursor to language. Certainly, music “has a generative structure similar to that of language” (Corballis, 269), and Corballis goes further to suggest as I am, that “Given the rather diffuse yet pervasive quality of music in human society, it may well have been a precursor to language, perhaps even providing the raw stuff out of which generative grammar was forged” (269). Language likely emerged from the bifurcation of ape-song into music and language. Poetry/song reintegrates the two. Which helps explains it's power as a literary art.