Energy conserving schemes for the simulation of musical instrument contact dynamics

Collisions are an innate part of the function of many musical instruments. Due to the nonlinear nature of contact forces, special care has to be taken in the construction of numerical schemes for simulation and sound synthesis. Finite difference schemes and other time-stepping algorithms used for musical instrument modelling purposes are normally arrived at by discretising a Newtonian description of the system. However because impact forces are non-analytic functions of the phase space variables, algorithm stability can rarely be established this way. This paper presents a systematic approach to deriving energy conserving schemes for frictionless impact modelling. The proposed numerical formulations follow from discretising Hamilton׳s equations of motion, generally leading to an implicit system of nonlinear equations that can be solved with Newton׳s method. The approach is first outlined for point mass collisions and then extended to distributed settings, such as vibrating strings and beams colliding with rigid obstacles. Stability and other relevant properties of the proposed approach are discussed and further demonstrated with simulation examples. The methodology is exemplified through a case study on tanpura string vibration, with the results confirming the main findings of previous studies on the role of the bridge in sound generation with this type of string instrument.

(Dis‑)Harmony in movement: effects of musical dissonance on movement timing and form

While the origins of consonance and dissonance in terms of acoustics, psychoacoustics and physiology have been debated for centuries, their plausible effects on movement synchronization have largely been ignored. The present study aims to address this by investigating whether, and if so how, consonant/dissonant pitch intervals affect the spatiotemporal properties of regular reciprocal aiming movements. We compared movements synchronized either to consonant or to dissonant sounds, and showed that they were differently influenced by the degree of consonance of the sound presented. Interestingly, the difference was present after the sound stimulus was removed. In this case, the performance measured after consonant sound exposure was found to be more stable and accurate, with a higher percentage of information/movement coupling (tau-coupling) and a higher degree of movement circularity when compared to performance measured after the exposure to dissonant sounds. We infer that the neural resonance representing consonant tones leads to finer perception/action coupling which in turn may help explain the prevailing preference for these types of tones.

Emotions and voting in EU referendums

There is an emerging scholarship on the emotional bases of political opinion and behaviour and, in particular, the contrasting implications of two distinct negative emotions - anger and anxiety. I apply the insights in this literature to the previously unresearched realm of the emotional bases of voting in EU referendums. I hypothesise that anxious voters rely on substantive EU issues and angry voters rely on second-order factors relating to domestic politics (partisanship and satisfaction with government). Focusing on the case of Irish voting in the Fiscal Compact referendum, and using data from a representative sample of voters, I find support for the hypotheses and discuss the implications of the findings for our understanding of the emotional conditionality of EU referendum voting. 

Inhabiting Sound: Tactile-sonic links in musical meaning

Connections can be suggested between music’s occupation of physical space, its relative ‘presence’ (using Edward Hall’s notion of proxemics), and the various senses of movement which pervade it. Movement might be seen to operate with respect to music at a variety of levels of metaphorisation – as increasingly complex chains of analogy which point back to our early physical experience of the world. But of course music is, fundamentally, action. Humans put energy into systems - external or internal to themselves - which transduce that energy into the movement of air. At the acoustic level music is, emphatically and unmetaphorically, movement. Perhaps such simple physical perceptions form one route through which we might understand and explore shared senses of meaning and their capacity for ‘transduction’ between multiple individuals. Our (developmentally) early sensory models of the world, built from encounters with its physical resistances and affordances, might be a route to understanding our more clearly encultured and abstracted ('higher' level) understandings of music.

Emotions and Power: Reconciling Conceptual Twins

While the existence of an ‘emotional turn’ within the social sciences is now widely acknowledged, some areas have garnered less specific attention than others. Perhaps the most significant absence within this literature is an explicit exploration of the relationship between emotions and relations of power and domination. This article will attempt such an endeavour. In doing so, I will draw on some key work from within the sociology of emotions, such as Barbalet, Collins, Kemper and Turner, and from the power literature within social theory more generally, including Dahl, Elias, Foucault, Giddens, Gramsci and Lukes. The main thrust of the argument is that power and emotion are conceptual twins in need of a serious theoretical reunion, and that emotions have played a largely unacknowledged, ‘under-labouring’ role within most theories of power. The need for a more unified approach to these two concepts is highlighted.