Timbrally

Perimeter Drive explores the potential for a single instrument to function timbrally, harmonically, and rhythmically as a multiple resource.

The first represents the degree of variation of successive harmonic peaks in the spectrum (this would indicate a timbrally rich music); the second, the relative strength of a tonal centre (e.g. a stable, predictable music); and the third, the degree of minor-to-major tonality, so that a higher value is ‘more major’ (see [30 ], p. 112, 127, and 129).