Why is Music Based on Scales?

Krzysztof Guczalski

Abstract

The spectrum of audible tone pitches is continuous: between every pair of tones there are numerous intermediate pitches. Yet from this potentially infinite resource, music chooses a very limited number of pitches, which constitute the musical system and the scales created within it.

Basing music on scales stands in distinct asymmetry with the plastic arts, for example. Painting does not confine itself to any choice of colours within the continuous spectrum of shades, and every painter may draw freely from the whole, potentially infinite, range. The question arises, therefore, as to why this occurs in music. The answers one encounters in the subject literature seem rather unsatisfactory. It is suggested that the existence of scales results from the use of notation, the needs of music pedagogy and the tradition of music analysis. Such answers are utterly implausible in light of the evidence that scales have been employed by all known musical cultures, including the purely oral. Further suggestions are that the existence of scales is conditioned by biological factors controlling musical production and perception and that they result from the categorical nature of perception. Yet none of these answers holds up to closer scrutiny.

Thus two other answers are proposed. First, that given the impermanence of music, which lasts only as long as it is played or sung, the possibility of its repeated performance depends on human memory, and the limitations of that memory made it necessary to narrow down the pitch material of music. Secondly, that the preference for consonance over dissonance gave rise to the phenomenon of the scale, which highlights and distinguishes consonances; allowing the whole gamut of pitches, meanwhile, would lead to the clear dominance of dissonances, which might be perceived as undesirable.

Further analysis shows that only the first of these two answers is plausible. It is supported by the fact that the surmounting of the impermanence of music, manifest in the creation of works ‘for tape’ – recorded in the creative process by the composer – at the same time enabled music to abandon scales for the first time and draw on the full gamut of pitches, and crucially on a considerably broader range of sounds – not just tones with a harmonic spectrum, but also various kinds of noise.