Metrical Displacement and Group Interaction in ‘Evidence’ by the Thelonious Monk Quartet

Jazz pianist Thelonious Monk is known for his rhythmically complex compositions and improvisations. His typical 32-bar AABA form pieces provide a framework of musical norms in terms of harmonic movement, and thus a point of reference for the harmonic rhythm to be displaced. ‘Evidence’ is exemplary of Monk’s displaced rhythms, which creates a sense of metrical shifts during the head arrangement. Composed c.1948 and a frequent piece of Monk’s performance repertoire into the 1970s, a transcription and analysis of the recording from Thelonious Monk Quartet Plus Two at the Blackhawk demonstrates a conflicting sense of metre between band members of the quartet. This chapter investigates how the musicians negotiated metrical discrepancies in the composed section and the saxophone solo in terms of group interaction. A mediation of time is demonstrated by a displaced metre in the drums and each musician’s performative response to the discrepancy by providing musical signals during the course of performance. Through analysis of this performance, the chapter examines the way in which the musicians arbitrated a decisive point of reference within a confounding performance of overturning the beat. This chapter contributes to understanding rhythm and metre through improvisatory processes, augmenting scholarship on jazz through its analysis of the temporal constituents of group interaction.

Congenital amusia—pathology of musical disorder

Amusia also known as tone deafness affects roughly 1.5% population. Congenital amusia appears from birth and lasts over life span. Usually, it is not associated with other diseases. Its link to hearing impairment has been definitively excluded. Neurobiological studies point to asymmetrical processing of musical signals in auditory cortex of left and right brain hemispheres. The finding was supported by discovering microlesions in the right-side gray matter. Because of its connection with asymmetry, amusia has been classified to disconnection syndromes. Alternatively to the neurobiological explanation of amusia background, an attention was turned to the significance of genetic factors. The studies done on relatives and twins indicated familial aggregation of amusia. Molecular genetic investigations linked amusia with deletion of 22q11.2 chromosome region. Until now no specific genes responsible for development of amusia were found.

Why musical hierarchies?

Credible signaling may have provided a selection pressure for producing and discriminating increasingly elaborate proto-musical signals. But why evolve them to have hierarchical structure? We argue that the hierarchality of tonality and meter is a byproduct of domain-general mechanisms evolved for reasons other than credible signaling.

The evolutionary benefit of less-credible affective musical signals for emotion induction during storytelling

The credible signaling theory underexplains the evolutionary added value of less-credible affective musical signals compared to vocal signals. The theory might be extended to account for the motivation for, and consequences of, culturally decontextualizing a biologically contextualized signal. Musical signals are twofold, communicating “emotional fiction” alongside biological meaning, and could have filled an adaptive need for affect induction during storytelling.

Why musical hierarchies?

Credible signaling may have provided a selection pressure for producing and discriminating increasingly elaborate proto-musical signals. But, why evolve them to have hierarchical structure? We argue that the hierarchality of tonality and meter is a byproduct of domain-general mechanisms evolved for reasons other than credible signaling.

AUDIO SIGNALS CLIPPING DETECTION USING KURTOSIS AND ITS TRANSFORMS

This paper compares the results of subjective and objective assessments of the quality of speech and music signals distorted during clipping when large instantaneous signal values are replaced by a certain threshold constant or by values close to it. It was proposed in recent works to use kurtosis and some of its simple functional transforms such as reciprocal of kurtosis and square root of reciprocal of kurtosis as objective (instrumental) clipping value measures. This paper clarifies the results of a subjective assessment of the quality of speech and music signals distorted by clipping. A comparison of the obtained estimates allows one to conclude that the human auditory system is slightly more sensitive to the clipping of musical signals than to the clipping of speech signals, but this difference is small. Similarly, objective quality measures of clipped signals are almost equally sensitive to the clipping value of speech and music signals. An analysis of the variability of the kurtosis estimates, depending on the time of estimation, showed that the relative standard deviation of the kurtosis estimates is close to 10% for the analysis time interval of 1–40 s.