Performance instrumental de elementos musicais e sonoros discretos e não discretos através de uma superfície táctil visualmente configurável

Abstract

Technological evolution has made ubiquitous the presence of luminous image in most electronic devices (namely tablets and smartphones). This image, emitted by screens, is eminently changeable and has the potentiality to assume several visual dispositions of instrumental character. The problem arises from the tactile limitations inherent to a direct instrumental interaction in these devices, namely with the attack intensity and the continuous manipulation of sound. This research proposes the conciliation of luminous image and tactile pressure using two hardware solutions: the first, called hectographic prototype, joins a transparent tactile surface with pressure acquisition capacity of the XYZ axes to a conventional screen; the second, called tablet prototype, joins a load cell for pressure acquisition of the Z axis to a screen with tracking capacity of the XY axes. The visual scope of this research is focused, by conceptual delimitation, on the paradigm of the keyboard, justified by its large dissemination among the discrete systems and consequent transposition of the instrumental technique. In this sense, two software implementations are presented: the Base Instrument, for both prototypes, and the Continuum Screenboard, intended for the tablet prototype. The tactile scope is focused on the continuous and multidimensional acquisition of the XYZ (cmXYZ) axes, where the hardware solutions allow the continuous (non-discrete) performance of pitch, dynamics and timbre. The flexibility of the luminous image provides several discrete representations of the pitch, namely different scales (tonal and microtonal), transpositions (by movement degree and by readjustment degree), temperaments and visual referrals (alphanumeric, colours and guides). The resulting sounds achieved combine different continuous as well as discrete configurations of pitch, dynamics and timbre ranging from discretion to total continuity. Two types of continuous progression of the pitch (direct glissando and projected glissando) are presented, as well as several parameterizations of vibrato. Starting from the tablet prototype, generic examples of cmXYZ audio-visual interaction are presented, together with paths for software and hardware development. This research presents a particular view of the instrumental universe, prompting a reflection on the very concept of instrumentality, instrumental discretion and continuity, representation of the keyboard and collection of the associated instrumental corpus.

Date of Award	2019
Original language	Portuguese
Supervisor	Luís Gustavo Martins (Supervisor)