M.Ing. / An investigation is conducted into the dynamic behaviour of a music turntable. The dynamic behaviour of the pickup arm is investigated in detail. The dinamic behaviour of the pickup arm is important in the design of a turntable because it basicly acts as a frequency filter. The pickup arm is under damped and is consequently suseptable to excitation as certain frequencies. The aim of this study is to investigate the dynamic behaviour of the turntable experimentally and mathematically by simulation. Chapter 1 serves as the introduction to the study. As the study concerns the music turntable, it is opened with a short background study of music and the role which it plays in today’s society. This is followed by an introduction to dynamic systems in general after which it is shown that the music turntable may be classified as a dynamic system. Chapter 2 describes the construction and the functioning of the turntable. The different components of the turntable is defined and characterised. This is followed by an investigation into the factors that may have an effect on the dynamic behaviour of the turntable. Chapter 3 describes how the turntable was modeled. Firstly mechanical modeling in general is investigated. This is followed by a paragraph. concerning analogy in engineering. Simple models to describe the dynamic behaviour of the pickup arm is presented. The effect of different kinds of damping is investigated. A more complex model is developed and described. The mathematical method used to investigate this modelis also described. Chapter 4 describes the experimental work that was performed to verify the simulation "results. The aim of the experimental work is firstly described and. then followed by the description of the general experimental facilities. The excitation, measurement and data - processing is discussed -in detail. The procedure that was followed to find the transfer function of the pickup arm is set out. This is followed by describing the procedure that was followed to find the dynamic behaviour of the pickup arm when it is excited by an impulse, step and a sweep function. Chapter 5 discusses the experimental and theoretical methods that were used to obtain the constants which were used in the simulation. Values for most of the constants were obtained experimentally. The constants were obtained by comparing the dynamic behaviour of each component with the dynamic behaviour of a simple system that 'can be solved in the closed form. Chapter 6 discusses the results that were obtained by comparing the experimental and the simulation results, that were obtained for the different excitations. This is followed by a discussion about the complex excitations that are possible when a stilus is pulled along a groove. Chapter 7 consists of two paragraphs. The work that was done is briefly summarised and this is followed by an evaluation of this study.

abstract: Since 1999, a small group of groundbreaking orchestral works for turntables and orchestra has surfaced on the concert stage. These compositions explore the possibilities of the turntables and invite an intriguing fusion of musical cultures of the classically trained musician and the hip-hop DJ. Since DJ turntablists typically follow an improvised tradition and do not read music, the composer must find an effective means of notating the turntables and collaborate with the turntablist in the execution of the work. As interest in turntables composition grows, there is a need for discussion and a compositional guide with advice based on present day works. In effort to contribute a guide for turntablism composition, my research includes a historical and composer perspective that discusses turntables techniques, operation of the equipment, digital technology, hip-hop background, history of the instrument, and works of the past and present with musical excerpts pertaining to the notation and use of the turntables. Specific sources include: RPM by Nicole Lizée, Concerto for Trumpet, Turntables, and Orchestra by Paul Leary, Concerto for Turntables and Orchestra by Gabriel Prokofiev, and Stephen Webber's turntable method book The Art of the DJ Turntable Technique. Interviews with composers Prokofiev, Lizée, and Leary have provided important primary source information regarding their experience with turntablism composition and performance. Unrelated to the above research and attached as an appendix, my composition Andrew's Ritual for Bedtime for chamber orchestra is a single movement for choreographed dance that depicts a mother preparing her energetic young son for bed. The title references the nightly rituals parents undertake in order to prepare their children for bedtime. / Dissertation/Thesis / D.M.A. Music 2014

Cette version du mémoire a été tronquée des éléments de composition originale. Une version plus complète est disponible en ligne pour les membres de la communauté de l’Université de Montréal et peut aussi être consultée dans une des bibliothèques UdeM. / Ce texte présente le processus de composition ayant mené à la création de la performance Soft Revolvers. Cette œuvre repose sur la conception d’interfaces sur mesure, soit quatre toupies lumineuses évoquant les tables tournantes. Je situe la création d’un tel dispositif, connoté et totalement intégré au propos artistique, dans la continuité historique du Gesamtkunstwerk (œuvre totale). Cette perspective englobante permet de questionner tous les aspects qui affectent la réception d’une œuvre. J’exposerai donc comment la lutherie utilisée, la gestuelle développée, la forme musicale et la scénographie ont été articulées autour d’un concept central dans la performance Soft Revolvers. Je présenterai finalement deux autres œuvres connexes, la performance Tempo Deluxe, qui utilise les mêmes interfaces de toupies, et la pièce Lumens&Profits, qui revisite les mêmes thématiques et techniques de composition dans une version fixée. Cette mise en parallèle permettra de mieux cerner les limitations impliquées par la spécificité des interfaces, tout en faisant ressortir l’efficacité du dispositif créé sur mesure dans le contexte numérique. / This text examines the composition process leading to the creation of the performance Soft Revolvers. The work is based on performance specific interfaces: four luminous spinning tops that evoke turntables. These connoted devices, fully integrated in the artistic discourse, are located within the historic continuum of the Gesamtkunstwerk (total work of art). This holistic perspective allows the renegociation of all the aspects that might influence the reception of a performance. Each of these aspects - the digital instrumentation, the gestural language, the musical form and the scenography - is discussed and articulated around the central concept in Soft Revolvers. Finally, two related works are presented, the performance Tempo Deluxe, which uses the same spinning top interfaces, and the piece Lumens&Profits, which explores the same thematic material as Soft Revolvers in a fixed version. Comparing these works allows a better delineation of the limitations implied by the interfaces' specificity, while confirming the effectiveness of the performance specific device in the digital realm.