CordChord: A String Instrument with Optical Sensing

Jack E Hardwick, Stefano Fasciani, and Çağrı Erdem

Proceedings of the International Conference on New Interfaces for Musical Expression

Abstract:

This paper introduces CordChord, a hybrid musical instrument that sees the performer interact with two physical cords to control the pitch, amplitude, and timbre of a two-voice granular synthesiser. An existing method for tracking bowing parameters of string instrument performance is adapted to measure the displacement of the cords by the performer's fingers. The method is based on an array of optical distance sensors in combination with a regression machine learning model to predict the position at and the amount by which each cord is displaced from a baseline tensioned position. Capacitive strips on the back of the neck of the instrument afford additional timbral control. A preliminary user study suggests that performers find the system responsive and engaging to play, while highlighting the need to further improve the accuracy of the regression model to make the system more intuitive.

Citation:

Jack E Hardwick, Stefano Fasciani, and Çağrı Erdem. 2024. CordChord: A String Instrument with Optical Sensing. Proceedings of the International Conference on New Interfaces for Musical Expression. DOI: 10.5281/zenodo.13904796

BibTeX Entry:

  @article{nime2024_16,
 abstract = {This paper introduces CordChord, a hybrid musical instrument that sees the performer interact with two physical cords to control the pitch, amplitude, and timbre of a two-voice granular synthesiser. An existing method for tracking bowing parameters of string instrument performance is adapted to measure the displacement of the cords by the performer's fingers. The method is based on an array of optical distance sensors in combination with a regression machine learning model to predict the position at and the amount by which each cord is displaced from a baseline tensioned position. Capacitive strips on the back of the neck of the instrument afford additional timbral control. A preliminary user study suggests that performers find the system responsive and engaging to play, while highlighting the need to further improve the accuracy of the regression model to make the system more intuitive.},
 address = {Utrecht, Netherlands},
 articleno = {16},
 author = {Jack E Hardwick and Stefano Fasciani and Çağrı Erdem},
 booktitle = {Proceedings of the International Conference on New Interfaces for Musical Expression},
 doi = {10.5281/zenodo.13904796},
 editor = {S M Astrid Bin and Courtney N. Reed},
 issn = {2220-4806},
 month = {September},
 numpages = {6},
 pages = {104--109},
 presentation-video = {},
 title = {CordChord: A String Instrument with Optical Sensing},
 track = {Papers},
 url = {http://nime.org/proceedings/2024/nime2024_16.pdf},
 year = {2024}
}