Birdsong is commonly associated with the sound of a flute. Although the pure, often high pitched, tone of a bird is undeniably flutelike, its sound production mechanism more closely resembles that of the human voice, with the syringeal membrane (the bird’s primary vocal organ) acting like vocal folds and a beak acting as a conical bore. Airflow in the song bird’s vocal tract begins from the lungs and passes through two bronchi, two nonlinear vibrating membranes (one in each bronchial tube), the trachea, the mouth, and finally propagates to the surrounding air by way of the beak. Classic waveguide synthesis is used for modeling the bronchi and trachea tubes, based on the model of Fletcher [J. Acoust. Soc. Am. (1988, 1999)]. The nonlinearity of the vibrating syringeal membrane is simulated by finite‐difference methods. This nonlinear valve, driven by a steady pressure from the bronchi, generates an oscillatory pressure entering the trachea.