The idea that listeners’ tonal/atonal sense represents a special case of multiple causation was examined, and the following hypothesis was tested: pitch dispersal (i.e., distance in pitch between successive tones) is a secondary determiner of tonality and atonality, the former being strengthened by low levels of pitch dispersal and the latter by high levels of pitch dispersal. A correlational study was conducted in which eight trained listeners judged the degree to which 78 melodies extracted from A. Schoenberg’s oeuvre convey a tonic. In line with the present hypothesis, results suggest that listeners’ judgments were influenced not only by consonance or pitch class distributions (i.e., by underlying “scales”), as expected from previous research, but also by pitch dispersal. Interestingly, it was also found that Schoenberg’ melodies became not only less diatonic over time, but also more dispersed, which suggests that the joint manipulation of pitch class distributions and pitch dispersal might have been a strategy on Schoenberg’s part to weaken the sense of tonality. Some of the key musicological, theoretical, and psychological implications of these findings are discussed.
Two experiments investigated the role of pitch-related information in tonality induction. In both experiments, participants were asked to: 1) identify (sing) the tonic of either an original sequence of tones or a distorted version in which pitch class distribution was preserved but pitch class ordering, pitch contour, and/or pitch proximity were altered; and 2) rate how confident they were in the tonic they identified. In Experiment 2, the sequences were presented with an isochronous rhythm, in order to eliminate the potential confounding effects of time-related information. The results of both experiments showed that participants’ ability to identify the tonic of the sequences, as well as their confidence in the tonic they identified, decreased when pitch class ordering was distorted, and also when pitch proximity was reduced. This suggests that tonality induction not only involves the identification of abstract pitch class structures, but it also acts as a pattern-matching process.