Prevalence of octave equivalence in vocal and instrumental practices

Ascertain whether octave equivalence is practiced in the musical traditions represented by the Vocal and Instrumental scale datasets and determine its cross-cultural prevalence to inform scale categorization and modeling.

Background

Octave equivalence defines a special class of scales with cyclical pitch relations and is assumed by theoretical (prescriptive) scales, whereas for descriptive Vocal and Instrumental scales octave equivalence must be inferred from performance practice.

The authors refrain from categorizing Vocal and Instrumental scales as octave scales because of uncertainty about practitioners’ use of octave equivalence, which has implications for model construction, interval counting, and interpretation of harmonic biases across datasets.