  A new definition of musical pitch is proposed. A Finite-Difference Time
Domain (FDTM) model of the cochlea is used to calculate spike trains caused by
tone complexes and by a recorded classical guitar tone. All harmonic tone
complexes, musical notes, show a narrow-band Interspike Interval (ISI) pattern
at the respective fundamental frequency of the tone complex. Still this
fundamental frequency is not only present at the bark band holding the
respective best frequency of this fundamental frequency, but rather at all bark
bands driven by the tone complex partials. This is caused by drop-outs in the
basically regular, periodic spike train in the respective bands. These
drop-outs are caused by the energy distribution in the wave form, where time
spans of low energy are not able to drive spikes. The presence of the
fundamental periodicity in all bark bands can be interpreted as pitch. Contrary
to pitch, timbre is represented as a wide distribution of different ISIs over
bark bands. The definition of pitch is shown to also works with residue
pitches. The spike drop-outs in times of low energy of the wave form also cause
undertones, integer multiple subdivisions in periodicity, but in no case
overtones can appear. This might explain the musical minor scale, which was
proposed to be caused by undertones already in 1880 by Hugo Riemann, still
until now without knowledge about any physical realization of such undertones.
