Quartet For Strings, by Stephen David Beck, was performed by the Laptop Orchestra of Louisiana in July 2016 at the International Conference on New Interfaces for Musical Expression (NIME) in Brisbane, Australia. Performers were Stephen David Beck, Edgar Berdahl, Andrew Pfalz, and Eric Sheffield. The virtual string model was designed by Edgar Berdahl.

 

 

Virtual slack strings are designed for and employed by the Laptop Orchestra of Louisiana. These virtual strings are slack in the sense that they can be very easily displaced, bent, tugged upon, etc. This enables force-feedback control of widely ranging pitch glides, by as much as an octave or more, simply by bending the virtual string. To realize a slack string design, a virtual spring with a specific nonlinear characteristic curve is designed. Violin, viola, and cello-scale models are tuned and employed by the Laptop Orchestra of Louisiana in Quartet for Strings.

 

 

This is a visualization of how the virtual slack string works.