Influences of structure and agency on the perception of musical change.

Abstract

In previous work, we and others have shown that continuous perceptions of change in an ongoing piece of music can be significant predictors of nonmusicians' continuous perception of the affect expressed by the piece (Bailes & Dean, 2012; Dean & Bailes, 2010), as can other continuous features such as acoustic intensity (Dean, Bailes, & Schubert, 2011; Schubert, 1999, 2004). Yet some evidence has suggested that such nonmusicians are fairly indifferent to large structural features. For example, the global liking of classical music and its perceived expression are little perturbed when sections are shuffled (Eitan & Granot, 2008), when tonal music is presented without tonal closure (Cook, 1987) or after conversion into atonal music of otherwise similar structure (Lalitte, Bigand, Kantor-Martynuska, & Delbe, 2009). This might indicate that musical sections are not explicitly perceived. On the other hand, evidence concerning Roger Reynolds' Angel of Death (for instruments and computer sound) suggests that sectionalisation was indeed perceived in this work (McAdams, Vines, Vieillard, Smith, & Reynolds, 2004). This large-scale concert experiment involved a minority of nonmusicians, but participants could often recognize recurrences of musical material. In this experiment, the task demand to focus continuously on familiarity or resemblance within the piece related explicitly to large-scale structure.The ambiguities in the results just summarized led us to seek to establish whether large-scale musical structures and features of agency (such as solo vs. orchestral sections in a concerto) are reflected in nonmusicians' continuous perceptions of change in music, and to minimize the demand characteristics of the experimental task. Given the disparities about perceptions of large-scale structure under explicit (demand-driven) test conditions, we hypothesized that an impact of large-scale musical structure on continuous perception of local musical change could be detected, and this would provide an implicit measure, without an explicit demand-driven focus on perceiving large-scale structure. Specifically, we hypothesized that large-scale musical segments would predict perceptual response regime-shifts, points which separate segments of different characteristics within the overall response time series. We second hypothesized that such relationships between large-scale musical structure and continuous perception of change would hold within non-Western music, unfamiliar to our nonmusician listeners, as well as in potentially more familiar music. So we investigated this issue with respect to a diverse range of acoustic and electroacoustic pieces from several cultures and periods.Our analysis of continuous perceptual ratings detects statistical in the response time series. This common terminology is slightly misleading: such analyses do not simply detect special features at a particular point, but rather, differences between the overall characteristics of successive segments of the temporal data series. Two of the pieces studied comprise only a single musical segment: if musical segments were the only influence, then no perceptual changepoints would be found in these. However, previous work also shows that surface features, such as short-term changes in acoustic intensity, strongly influence perceived change (Dean & Bailes, 2010); hence, we expect that segments will be perceived in these structurally uniform pieces, and that there will be perceptual segments in the structurally varied works besides those reflecting the musicological structure. The key test of our primary hypothesis is therefore whether the musicological segments coincide with perception changepoints, accepting that additional changepoints may be expected.One might theorise that inexperienced listeners would lack the ability to group and hierarchically organize the low-level features of the music as it flows: they might not be able to transform perceptions at a fine-grained temporal resolution (continuous change) into those in a larger time frame (musical structure). …