A platform for low-latency continuous keyboard sensing and sound generation

On several acoustic and electromechanical keyboard instruments, the produced sound is not always strictly dependent exclusively on a discrete key velocity parameter, and minute gesture details can affect the final sonic result. By contrast, subtle variations in articulation have a relatively limited effect on the sound generation when the keyboard controller uses the MIDI standard, used in the vast ma-jority of digital keyboards. In this paper we present an embedded platform that can generate sound in response to a controller capable of sensing the continuous position of keys on a keyboard. This platform enables the creation of keyboard-based DMIs which allow for a richer set of interaction gestures than would be possible through a MIDI keyboard, which we demonstrate through two example instruments. First, in a Hammond organ emulator, the sensing device allows to recreate the nuances of the interaction with the original instrument in a way a velocity-based MIDI controller could not. Second, a nonlinear waveguide flute synthesizer is shown as an example of the expressive capabilities that a continuous-keyboard controller opens up in the creation of new keyboard-based DMIs.