From ornithology recordings, Bapista conjures much of an orchestra. For oboe, for example, he selects the Australian diamond firetail finch, and for flute, he picks the long whistles of the white-bellied green imperial pigeon and the descending run of short notes uttered by the strawberry finch. He elects as bassoonist the common potoo, with a call that reminds him of the beginning of Mozart's clarinet quintet, albeit slightly off-key. Ornithologists have noted birdsongs pitched to the same musical scales used by people, Baptista points out. Such musical phenomena as the borrowing of melodies, singing in duets or duels, and passing down traditions through families from generation to generation also show up in birds, Baptista reports.
Some species even compose in sonata form.
The sparrow eventually burbles the original theme again, a version of a sonata's final recapitulation. The similarity between bird and human sonatas is more than coincidence, Baptista argues. This maxim governs people, too, Baptista says, and a composer's variations on a theme catch the attention through novelty. However, unrelieved novelty eventually exhausts the perceiver, and a reference to the familiar relieves the fatigue. Birds and people share these reactions, Baptista argues, so he's not surprised that they also share composition strategies.