Eugene Morton of the National Zoo years ago came up with his "motivation structure" theory to explain why, when factors of pitch and timing are renormalized so that acoustically analyzed (fast fourier) animal vocal signals all are fitted into the same window visually, so many different vertebrates (birds, mammals, etc.) seemed to have largely the "same" signal repertoire. That is, when a shrew chirps, a dog barks, and an elephant roars its the same signal, despite superficial differences having to do with scaling.

Besides pitch (rising, falling, arched, flat), these signals utilize smoothness or roughness, and other features that human language also does.

The most interesting aspect of the theory, taken together with findings from nonvocal signal work, is that visual and other modalities seem to utilize similarly interpreted features- which is maybe why we can also have sign language (which is highly iconic).

There is also evidence that the brain itself utilizes these feature parameters in its own functioning, suggesting that the external signals merely use convenient modalities to communicate brain to brain, as best as each modality will allow. Even invertebrates may share in this. Quite fascinating. But it isn’t music.

telescopeguy