The Bowed Tube: a Virtual Violin

This paper presents a virtual violin for real-time performances consisting of two modules: a violin spectral model and a control interface. The interface is composed by a sensing bow and a tube with drawn strings in substitution of a real violin. The spectral model is driven by the bowing controls captured with the control interface and it is able to predict spectral envelopes of the sound corresponding to those controls. The envelopes are filled with harmonic and noisy content and given to an additive synthesizer in order to produce violin sounds. The sensing system is based on two motion trackers with 6 degrees of freedom. One tracker is attached to the bow and the other to the tube. Bowing controls are computed after a calibration process where the position of virtual strings and the hair-ribbon of the bow is obtained. A real time implementation was developed as a MAX/MSP patch with external objects for each of the modules.