Fig. 3: Pitch-class distribution of the 2301 scale tones for the unwrapped transposed representation of the full set of vocal scales.

A The histogram shows the probability density for the manually annotated scales (in bins of 1 semitone), while the solid line is a kernel density estimation (KDE; bandwidth = 0.025) plot for the semi-automatically annotated scales. The pitches are shown as semitones relative to the tonic after transposition to C (which is indicated by 0). The corresponding letter names are shown below them. Note that all tonic degrees are excluded from the graph since they are present, by definition, in 100% of the scales. For aid in visualization, the pitches in the central octave (C-C) are shown with darker bars. B A quantification of the number of pitches per scale. C A quantification of the number of different interval-sizes per scale.