New developments on the augmentation of a classical guitar: Addition of embedded sound synthesis and OSC communication over network Eduardo A. L. Meneses 1 , Marcelo M. Wanderley 1 1 Input Devices and Music Interaction Laboratory (IDMIL) Centre for Interdisciplinary Research in Music Media and Technology (CIRMMT) McGill University 550 Sherbrooke St. W. – Montreal, Quebec, Canada eduardo.meneses@mail.mcgill.ca, marcelo.wanderley@.mcgill.ca The classical nylon string guitar is a versatile musical instrument that can generate a wide va- riety of timbres, but other characteristics such as the short sustain and the lack of sound intensity control after the attack are usually considered se- vere restrictions imposed by the physical struc- ture of the instrument. One of the approaches to solve these problems is the construction of augmented musical instru- ments (AMIs). Using sensors and actuators it is possible to generate gestural data that can be used to control specific software programed to address these issues using digital signal process- ing (DSP). The GuitarAMI aims to use gestural data to control algorithms that overcome the restric- tions described above [1]. GuitarAMI explores possibilities of modification of the commonly considered restrictive intrinsic characteristics of the acoustic guitar by using sensors that gen- erate data trough effective and free gestures [2], controlling sound manipulation patches pro- grammed in Pure Data [3]. The Pure Data patch modifies the sustain time by performing a Fast Fourier Transform (FFT) to analyze the audio signal and later re-synthesizes a sound that can be sustained indefinitely. One of the major problems encountered dur- ing the use of previous GuitarAMI prototypes was the difficulty of system setup for perfor- mances. In the first prototypes the number of connections and cables increased the possibility of malfunctioning and made the instrument less robust. With the third prototype there was some improvement regarding setup time but the instru- ment still had not reached the robustness required for plug-and-play use by performers. Figure 1: GuitarAMI new prototype, constructed using the ESP8260 WiFi microcon- troller, ultrasonic sensor and accelerometer. Embedding a single-board computer and an audio interface into the GuitarAMI base can si- multaneously increase robustness and make the AMI more usable by the performer. We chose the Raspberry Pi 3 model B due to its unique quali- ties: As it is an open-source hardware platform we have a greater range of compatible boards and components. In addition, the Raspberrry Pi SBCM 2017 16th Brazilian Symposium on Computer Music 168 S˜ ao Paulo – Brazil