Statistics of D. melanogaster song. (a) Mean (per individual) re-scaled pulse shapes from five wild-type strains: Antigua = light blue; Beltsville = green; CS-Tully = purple; Oregon-R = red; Taiwan = dark blue. The same colors indicate strains in later panels. (b) Histogram of inter-pulse intervals over the entire dataset. Inset illustrates the distribution for one individual. A two-component Gaussian mixture model (dark line) and the two Gaussian components (light lines) are shown fitted to the data. (c, d) The average pulse (c) and sine train (d) carrier frequencies vary between individuals and amongst strains. (e) The mean inter-pulse interval, here shown for the lower component of a Gaussian mixture model, showed considerable variation amongst strains. (f) The relative amounts of sine and pulse trains were treated as a "three-way choice' - between sine train, pulse train, and no song - and plotted as recommended by Schilling et al. . This method reveals that flies that produced more song overall sang proportionately fewer sine trains relative to pulse trains. In addition, strains displayed significant heterogeneity in the relative amounts of sine and pulse trains that they produced. (g,h) Both pulse train length (g) and sine train length (h) exhibit variation amongst strains. (i-k) The duration of all pauses between song bouts (i), the duration of pulse trains (j), and the duration of sine trains (k) each exhibit extensive variation.