Expressing Tonal Closure in Music Performance: Auditory and Visual Cues

We examined whether musical performers communicate tonal closure through expressive manipulation of facial expressions and non-pitch features of the acoustic output. Two musicians hummed two versions of Silent Night: one ended on the tonic of the scale and exhibited tonal closure; the other ended on the dominant and was therefore tonally unclosed. In Experiment 1, video-only recordings of the hummed sequences were presented to 15 participants, who judged whether the (imagined) melody was closed or unclosed. Accuracy was reliably above chance, indicating that the musicians expressed tonal closure in facial expressions and listeners decoded these cues. Experiment 2 was conducted to determine whether musicians also communicate tonal closure in acoustic attributes other than pitch. All tones in the hummed melodies were pitched-shifted to a constant mean value, but performances still differed in loudness, microtonal pitch variation, timing, and timbre. Participants judged whether audio-only recordings were closed or unclosed. Accuracy was not above chance overall, but was marginally above chance for judgement of one of the two singers. Results suggest that tonal closure can be mapped onto non-pitch aspects of performance expression, but is primarily restricted to the use of facial expressions.