GASP: Guitars with ambisonic spatial performance

2021

The term sound spatialisation indicates a group of techniques for organizing and manipulating the spatial projection and movement of sound in a physical or virtual listening environment (Valiquet, 2011). In addition to pitch, timbre, intensity and duration, an understanding of space is a significant musical parameter and as such, spatial sound controllers should be regarded as instruments of musical expression (Pysievficz and Weinzierl, 2016); spatialiser design should therefore include immediacy, liveness, and learnability. Perez-Lopez (2015) identifies several design considerations for spatialisation systems, including: Is the performer exclusively controlling spatial parameters (in contrast to one who controls both spatialisation and sound generation)? What is the required level of expertise for expressivity and virtuosity? Is the spatial control made by an individual, or shared by a group of performers? Does the system provide a graphical user interface for real time visual feed...

Proceedings of the SMC Conferences, 2013

2018

This work studies the use of signal-driven synthesis algorithms applied to an augmented guitar. A robust sub-octave generator, partially modeled after a classic audio-driven monophonic guitar synthesizer design of the 1970s is presented. The performance of the proposed system is evaluated within the context of an augmented active guitar with an actuated sound box. Results of the evaluation show that the design represents an exciting augmentation for the instrument, as it radically transforms the sound of the electric guitar while remaining responsive to the full range of the guitar playing gestures.

The 21st Century Guitar: Volume 1: Proceedings of The 21st Century Guitar Conference 2019 & 2021 Article 12, 2021

The GASP project investigates the design and realisation of an Immersive Guitar System. It brings together a range of sound processing and spatialising technologies and applies them to a specific musical instrument ‒ the Electric Guitar. GASP is an ongoing innovative audio project, fusing the musical with the technical, combining the processing of each stringʼs output (which we called timbralisation) with spatial sound. It is also an artistic musical project, where space becomes a performance parameter, providing new experimental immersive sound production techniques for the guitarist and music producer. Several ways of reimagining the electric guitar as an immersive sounding instrument have been considered, the primary method using Ambisonics. However, additionally, some complementary performance and production techniques have emerged from the use of divided pickups, supporting both immersive live performance and studio post-production. GASP Live offers performers and audiences new real-time sonic-spatial perspectives, where the guitarist or a Live GASP producer can have real-time control of timbral, spatial, and other performance features, such as: timbral crossfading, switching of split-timbres across strings, spatial movement where Spatial Patterns may be selected and modulated, control of Spatial Tempo, and real-time performance re-tuning. For GASP recording and post-production, individual string note patterns may be visualised in Reaper DAW,2 from which, analyses and judgements can be made to inform post-production decisions for timbralisation and spatialisation. An appreciation of auditory grouping and perceptual streaming (Bregman, 1994) has informed GASP production ideas. For performance monitoring or recorded playback, the immersive audio would typically be heard over a circular array of loudspeakers, or over headphones with head-tracked binaural reproduction. This paper discusses the design of the system and its elements, investigates other applications of divided pickups, namely GASPʼs Guitarpeggiator, and reflects on productions made so far.

2016

Music representation has been a widely researched topic through centuries. Transcription of music through the conventional notation system has dominated the field, for the best part of the last centuries. However, this notational system often falls short of communicating the essence of music to the masses, especially to the people with no music training. Advances in signal processing and computer science over the last few decades have bridged this gap to an extent, but conveying the meaning of music remains a challenging research field. Music visualization is one such bridge, which we explore in this work. This research presents an approach to visualize guitar performances, transcribing musical events into visual forms. To achieve this, hexaphonic guitar processing is carried out (i.e. processing each of the six strings as an independent monophonic sound source) to get music descriptors, which reflect the most relevant features of a sound to characterise it. Once this information is...

This paper describes two augmented nylon-string guitar projects developed in different institutions. GuitarAMI uses sensors to modify the classical guitars constraints while GuiaRT uses digital signal processing to create virtual guitarists that interact with the performer in real-time. After a bibliographic review of Augmented Musical Instruments (AMIs) based on guitars, we present the details of the two projects and compare them using an adapted dimensional space representation. Highlighting the complemen-tarity and cross-influences between the projects, we propose avenues for future collaborative work.

2019

This paper reports the conception, design, implementation and evaluation processes of PICO, a portable audio effect system created with Pure Data and the Raspberry Pi, which augments traditional plucked string instruments such as the Brazilian Cavaquinho, the Venezuelan Cuatro, the Colombian Tiple and the Peruvian/Bolivian Charango. A fabric soft case fixed to the instrument`s body holds the PICO modules: the touchscreen, the single board computer, the sound card, the speaker system and the DC power bank. The device audio specifications arose from musicological insights about the social role of performers in their musical contexts and the instruments' playing techniques. They were taken as design challenges in the creation process of PICO`s first prototype, which was submitted to a short evaluation. Along with the construction of PICO, we reflected over the design of an interactive audio interface as a mode of research. Therefore, the paper will also discuss methodological aspec...

2014

The idea behind the YouHero was two-fold: First, to make an expressive instrument out of the computer game toy guitar controller from the famous game GuitarHero. With its limited amount of control parameters, this was a challenge. Second, we wanted to provide an alternative to the view that you become a hero by perfect imitation of your idols. Instead, play yourself. You are the hero. In this paper, we describe the design of the instrument, including its novel mapping approach based on switched timbre vectors scaled by accelerometer data, unconventional sound engines and the sound and mapping editing features, including manual editing of individual vectors. The instrument is evaluated through its practical applications during the whole project, with workshops with teenagers, a set of state-funded commissions from professional composers, and the development of considerable skill by the key performers.

2009

This project aims at studying how recent interactive and interaction technologies would help extend how we play the guitar, thus defining the “multimodal guitar”. We investigate two axes, 1) “A gestural/polyphonic sensing/processing toolbox to augment guitar performances”, and 2) “An interactive guitar score following environment for adaptive learning”. These approaches share quite similar technological challenges (sensing, analysis, processing, synthesis and interaction methods) and dissemination intentions (community-based, low-cost, open-source whenever possible), while leading to different applications (respectively artistic and educational), still targeted towards experienced players and beginners. We designed and developed a toolbox for multimodal guitar performances containing the following tools : Polyphonic Pitch Estimation (see section 3.1.1), Fretboard Grouping (see section 3.1.2), Rear-mounted Pressure Sensors (see section 3.2), Infinite Sustain (see section 3.3.2), Rear...