ORGANIZING AND RECOGNIZING MUSICAL TENSION/RELEASE PATTERNS MAY BE CULTURE DEPENDENT
Performing and listening to an improvisation on the Middle Eastern mijwiz

Pantelis N. Vassilakis, Ph.D.
DePaul University School of Music
804 W. Belden Ave. Chicago, IL 60614-3250
http://www.acousticslab.com - pantelis@acousticslab.com
 
Popular version of paper 3aMU5
Presented Wednesday morning, May 18, 2005
149th ASA Meeting, Vancouver, BC, Canada

Overview: Musical tension/release and auditory roughness contrasts

Our ability to attach meaningful and emotional qualities to instrumental pieces of music relies, to a large extent, on our recognition of potential musical tension/release patterns within a piece. Such patterns can be set up using a variety of sonic and sonic-organization tools, whose significance and potential to communicate meaning and emotion appears to largely depend on previous small-scale (personal) and large-scale (cultural) learning.

Within the Western musical tradition, studies have shown that musical tension/release judgments are linked to contrasts in terms of: i) tonal center (e.g. key), ii) sensory dissonance, iii) dynamics, iv) pitch, v) rhythm, vi) orchestration, vii) performance techniques, etc., with sensory dissonance correlating with the presence of auditory roughness. The term auditory roughness describes a rattling sound associated with certain types of signals such as those of narrow harmonic intervals. The potency of the suggested contrasts depends on familiarity with musical norms that are, largely, culturally defined.
As the above list suggests, auditory roughness contrasts within a piece constitute just one of the sonic tools (cues) that help set-up (determine) musical tension/release patterns. In addition, the strong link, within Western tradition, between roughness and annoyance, and the assumption that rough sounds should be avoided, limit the range of roughness variations explored, further reducing the contribution of auditory roughness contrasts to the organization and recognition of musical tension and release. As we will see, the situation may be quite different when it comes to non-Western musical traditions.

A Matter of Audience: Auditory roughness contrasts in non-Western musical traditions

Performance practices outside the Western art musical tradition explore a much wider roughness range, indicating that the sensation of roughness can be of much more importance in the production of musical sound and the communication of expressive intent. In many such cases, the increased importance of auditory roughness as a sonic and sonic-organization device is accompanied by a decrease in the importance of other relevant devices.

For example, the Middle Eastern mijwiz (two paired single-reed pipes) is constructed and performed in ways that limit the possibilities for extensive exploration of dynamic, pitch, tonal, and timbral (other than roughness) contrasts. More specifically, the mijwiz:
a) requires performers to maintain high pressure air-flow in order to sustain a steady tone, limiting its dynamic range;
b) is often performed using the circular breathing technique, limiting the possibilities for interplay between sound and silence;
c) has narrow melodic range (~a fifth) and limited harmonic menu (no melodic line crossing), resulting in limited possibilities for melodic/harmonic contrasts;
d) has two reeds that are activated just by air pressure (with no manipulation possible from the lips or tongue, as would be the case for a clarinet-like instrument), limiting the possibilities for timbral contrasts associated with vibrato or other forms of spectral manipulation.

For its expressive power, the mijwiz, like most double-pipes throughout history, relies mainly on the exploration of narrow harmonic intervals. Such explorations correspond to manipulation and exploration of roughness degrees, making musical pieces performed on the mijwiz good candidates for the examination of the relationship between roughness profiles and patterns of musical tension.

Click on the image to the right to see a performance of the mijwiz piece used in the present study.
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A Perceptual Study: Auditory roughness profiles and tension/release patterns in an improvisation on the Middle Eastern mijwiz

The present study examined a recording of a stylized improvisation on the mijwiz, performed by Prof. A. J. Racy, a Lebanese-born musician and scholar at the University of California, Los Angeles, Department of Ethnomusicology (click on the image above to see the performance).

The roughness profile of the recorded piece was estimated using a custom application that automates frequency analysis and roughness calculation of complex signals, at user-specified time intervals. The application is available online (http://www.acousticslab.com/roughness), including detailed descriptions of the relevant analysis and calculation methods. Briefly, the frequency analysis portion uses an improved STFT algorithm based on the Reassigned Bandwidth-Enhanced Additive Model by Dr. K. Fitz, while the roughness calculation portion is based on a roughness estimation model introduced and tested in a previous study by the author.

The roughness profile was compared to tension/release patterns indicated by the improviser and expert mijwiz player as well as by Western-trained musicians, in a perceptual experiment designed using Prof. R. A. Kendall's Music Experiment Development System (MEDS).
The results suggest that auditory roughness is a good predictor of the tension/release pattern indicated by the improviser. The patterns obtained by the subjects show a different trend. Auditory roughness appears to be just one of the cues guiding musical tension judgments, often overridden by tonal and temporal cues, as well as by expectations of tension/resolution raised by such cues.
Click on the image below to see a video clip of the results.

Discussion: Same musical piece different musical understandings

The results may be interpreted in terms of different listening strategies employed by the two different types of listeners, strategies that are related to musical expectations outlined by the different underlying musical traditions.

From the improviser's point of view, roughness contrasts created through frequent moves between narrow and unison harmonic intervals constitute musical expressive cues that are widely accepted and employed within the Near Eastern musical tradition to communicate changes in musical tension. Composers and performers incorporate these contrasts when setting up tension/release patterns and listeners look out for them, even if implicitly, when they organize perceptually and attach meaning to musical pieces.

From the point of view of listeners raised within the Western musical tradition, auditory roughness contrasts play a limited role when it comes to identifying musical tension/release patterns, while tonal and temporal contrasts provide more significant musical cues and set up stronger tension/resolution expectations. As a result, when Western raised/trained listeners are confronted with a musical piece such as the one used in the present study, they continue to employ their familiar strategies to parse the incoming sound, reaching an interpretation that differs from the composers / performers expressive intent.

The observed differences between the tension/release patterns obtained, correspond to differences in the way relevant (to each listener type) musical cues are laid out in time within the mijwiz piece. For example, points in the piece corresponding to high (low) roughness values but low (high) tonal or temporal 'load', coincide with high (low) tension judgments by the improviser but low (high) tension judgments by the Western-trained listeners. This supports the suggestion that musical tension and release are culture-specific concepts, guided by the equally culture-specific musical cues used to organize and recognize them.

Acknowledgements

Study supported by the Department of Instructional Technology Development and the School of Music, DePaul University. Special thanks to Profs. R. A. Kendall and A. J. Racy, Ethnomusicology Department, University of California, Los Angeles, for their expertise.