Self-Organizing "Harmonic Dominance Stripes" in a Spiking Network Model of the Auditory System A: Connectivity Matrix. After 500 trials, self-organizing "harmonic dominance stripes" had become clearly visible in the connectivity matrix between the two layers of neurons. Besides the "tonotopic" unison interval stripe along the diagonal, stripes corresponding to the octave and fifth intervals in Western music theory (see Figure 1B and 1C) were also clearly visible. The colorbar on the Right shows the strength of synaptic connections between neurons. B: Frequency ratios from 100 to 1000 Hz for Unison (red), Octave (yellow and white) and Perfect Fifth (green and cyan) intervals in Western music theory. C: Unison, Octave and Perfect Fifth Frequency ratios from Figure 1B superimposed over the STDP connectivity matrix from Figure 1A.