Animal researchers like Gisela Kaplan, Ph.D. and Irene Pepperberg, Ph.D., have determined that birds not only sing to communicate daily needs, many engage in sound play, most often when they’re alone, but sometimes also when humans are present.

Some species continually improvise their singing with new elements, phrases and sequences, reports Kaplan, a professor at the Research Centre for Neuroscience and Animal Behaviour at the University of New England, Australia. Nightingales and canaries are among the avian virtuosos, reinventing their repertoire in each successive season, while the brown thrasher may hold the record at close to 2,000 song types. Nightingales, she notes, organize their compositions according to rules of construction similar to the way humans use syntax. These birds even create distinctive phrases that identify individuals.

Kaplan’s own recordings of Australian magpies reveal how the bird’s voice moves across four octaves, varies its phrasing between staccato and legato, and embellishes sequences with vibrato, trills or deep overtones. More, it will close a completed song with a signature phrase, in much the same way that a painter initials a finished canvas.