A Hybrid Keyboard-Guitar Interface using Capacitive Touch Sensing and Physical Modeling

Physical modeling allows realistic guitar synthesis incorporating many expressive dimensions commonly employed by guitarists, including pluck strength and location, plectrum type, hand damping and string bending. Often, when a physical model is used in performance, most control dimensions go unused when the interface fails to provide a way to intuitively control them. Techniques as foundational as strumming lack a natural analog on the MIDI keyboard, and few digital controllers provide the independent control of pitch, volume and timbre that even novice guitarists achieve. This paper presents a hybrid interface based on a touch-sensing keyboard which gives detailed expressive control over a physically-modeled guitar. Most dimensions of guitar technique are controllable polyphonically, some of them continuously within each note. Mappings are evaluated in a user study of keyboardists and guitarists, and the results demonstrate its playability by performers of both instruments.