The conceptualisation of music in ancient Greek thought (V century B.C. – II century B.C.)

The focus of this dissertation is the analysis of the music-related philosophical passages from the 5th century B.C. to the 2nd century B.C. It aims to provide a multifaceted view towards music as a cultural phenomenon, which is based primarily on the philological and culturological explorations instead of the technical-musicological approach. The texts from our selected period attest that mousikē had an extremely broad conceptualisation which led to the attribution of the different, sometimes completely opposite value: from an insignificant performative practice to an activity which corresponds to the divine laws and directly affects the human soul. The discussed testimonia provide evidence of defining music both as an exclusively acoustic phenomenon and as a philosophically significant concept that oversteps the sonic definition. Our sources clearly demonstrate that mousikē was a polysemous term: it was understood as an interdisciplinary form of art (as the arts of the Muses), though it was also used to indicate the exclusively instrumental music or a philosophical concept, which does not necessarily define sound as its essential quality. The aim of this dissertation is to clarify the arguments behind each of these positions, to analyse whether such different modes of conceptualisation are compatible among themselves, and to see how they fit together into explaining what was understood as music in Antiquity. In this thesis we explore the conceptual framework of mousikē and analyse what enabled the musical thought to be worthy of the attention of the greatest philosophical minds. We will demonstrate that it was not the sound or the artistic practices that were central in the philosophical thought on music, but instead the embedded structural qualities that have correspondence to the universal proportions of the cosmic world and which are perceptible to the listeners through the medium of sound.

Active control of sound radiated by vibrating surfaces on a McLaren supercar

Sound radiators based on forced vibrations of plates are becoming widely employed, mainly for active sound enhancement and noise cancelling systems, both in music and automotive environment. Active sound enhancement solutions based on electromagnetic shakers hence find increasing interest. Mostly diffused applications deal with active noise control (ANC) and active vibration control systems for improving the acoustic experience inside or outside the vehicle. This requires investigating vibrational and, consequently, vibro-acoustic characteristics of vehicles. Therefore, simulation and processing methods capable of reducing the calculation time and providing high-accuracy results, are strongly demanded. In this work, an ideal case study on rectangular plates in fully clamped conditions preceded a real case analysis on vehicle panels. The sound radiation generated by a vibrating flat or shallow surface can be calculated by means of Rayleigh’s integral. The analytical solution of the problem is here calculated implementing the equations in MATLAB. Then, the results are compared with a numerical model developed in COMSOL Multiphysics, employing Finite Element Method (FEM). A very good matching between analytical and numerical solutions is shown, thus the cross validation of the two methods is achieved. The shift to the real case study, on a McLaren super car, led to the development of a mixed analytical-numerical method. Optimum results were obtained with mini shakers excitement, showing good matching of the recorded SPL with the calculated one over all the selected frequency band. In addition, a set of directivity measurements of the hood were realized, to start studying the spatiality of sound, which is fundamental to active noise control systems.