The importance of harmony perception in understanding tonal melodies has been extensively studied, but underlying processes of implied harmonic perception remain unexplored. This study explores how listeners perceive implied harmony in real-time while hearing tonal melodies by addressing two questions: How is each tone of a tonal melody harmonically interpreted and integrated into the previous tones? How do harmonic expectations of “what” chord will follow and “when” the chord change will occur affect the processing? Participants with music training listened to tonal melodies and responded to target tones by singing their pitches as quickly as possible. The target tones implied an expected or an unexpected chord; they occurred at expected or unexpected times. The results showed that sing-back reaction times (RTs) were shorter for: 1) tones implying an expected chord; and 2) chord changes occurring at expected times, suggesting that harmonic expectations facilitate the processing of tonal melodies. Also, RTs became shorter over the presentation of successive target tones implying the same chord, suggesting that implied harmony becomes clearer as more tones belonging to a single chord are presented.

Science since antiquity has asked whether mathematical relationships among acoustic frequencies govern musical relationships. Psychophysics rejected frequency ratio theories, focusing on sensory phenomena predicted by linear analysis of sound. Cognitive psychologists have since focused on long-term exposure to the music of one’s culture and short-term sensitivity to statistical regularities. Today evidence is rapidly mounting that oscillatory neurodynamics is an important source of nonlinear auditory responses. This leads us to reevaluate the significance of frequency relationships in the perception of music. Here, we present a dynamical systems analysis of mode-locked neural oscillation that predicts cross-cultural invariances in music perception and cognition. We show that this theoretical framework combines with short- and long-term learning to explain the perception of Hindustani rāgas, not only by encultured Indian listeners but also by Western listeners unfamiliar with the style. These findings demonstrate that intrinsic neurodynamics contribute significantly to the perception of musical structure.

WE INVESTIGATED PEOPLES' ABILITY TO ADAPT TO THE fluctuating tempi of music performance. In Experiment 1, four pieces from different musical styles were chosen, and performances were recorded from a skilled pianist who was instructed to play with natural expression. Spectral and rescaled range analyses on interbeat interval time-series revealed long-range (1/ f type) serial correlations and fractal scaling in each piece. Stimuli for Experiment 2 included two of the performances from Experiment 1, with mechanical versions serving as controls. Participants tapped the beat at ¼¼- and ⅛⅛-note metrical levels, successfully adapting to large tempo fluctuations in both performances. Participants predicted the structured tempo fluctuations, with superior performance at the ¼¼-note level. Thus, listeners may exploit long-range correlations and fractal scaling to predict tempo changes in music.

The goal of this study was to assess the ability of North American adults to synchronize and continue their tapping to complex meter patterns in the presence and absence of musical cues to meter.We asked participants to tap to drum patterns structured according to two different 7/8 meters common in Balkan music. Each meter contained three nonisochronous drumbeats per measure, forming intervals in a short-short-long (SSL) or a long-short-short (LSS) pattern. In the synchronization phase of each trial, participants were asked to tap in synchrony with a drum pattern that was accompanied by either a matching or a mismatching Balkan folk melody. In the continuation phase of the trial, the drum pattern was turned off and participants continued tapping the drum pattern accompanied by the same melody or by silence. Participants produced ratios of long to short inter-tap intervals during synchronization that were between the target ratio of 3:2 and a simple-meter ratio of 2:1. During continuation, participants maintained a similar ratio as long as the melody was present but when the melody was absent the ratios were stretched even more toward 2:1. Tapping variability and tapping position relative to the target locations during synchronization and ratio production during both synchronization and continuation showed that the temporal grouping of tones in the drum pattern was more influential on tapping performance than the particular meter (i.e., SSL vs. LSS). These findings demonstrate that people raised in North America find it difficult to produce complex metrical patterns, especially in the absence of exogenous cues and even when provided with musical stimuli to aid them in tapping accurately.

We measured modulations of neuroelectric gamma-band activity (GBA) as subjects listened to isochronous pure-tone sequences with embedded temporal perturbations. Perturbations occurred every 6�10 tones, and at the locus of the perturbation, tones occurred early, on time, or late. In the absence of perturbations, induced (non�phase-locked) GBA reached maximum power simultaneously with the occurrence of tone onsets, whereas evoked (phase-locked) GBA peaks were observed after onsets. During late perturbation trials, peaks in induced activity tended to precede tone onsets, and during early perturbation trials, induced peaks followed tone onsets. Induced peaks returned to synchrony after both types of perturbations. Early tones resulted in a marked increase in evoked GBA power at the locus of the perturbation. The latency of evoked GBA relative to tone onset, as well as some other features of the response, depended asymmetrically on the direction of the perturbation. The current results provide evidence for the synchronization of GBA during the perception of auditory rhythms, thus supporting the role of GBA in temporal expectancy.