Netychords: An Accessible Digital Musical Instrument for Playing Chords using Gaze and Head Movements

Research on Accessible Digital Musical Instruments (ADMIs) dedicated to users with motor disabilities, facilitated by the introduction of new sensors on the mass market during the last decades, has carved out an important niche within the scenario of new interfaces for musical expression. Among these instruments, Netytar, developed in 2018, is a hands-free ADMI enabling the performance of monophonic melodies, controlled using the gaze (for the selection of the notes) and the breath (for the control of the dynamics), through an eye tracker and an ad-hoc breath sensor. In this article we propose Netychords, a Netytar extension developed to allow a quadriplegic musician to play chords. The instrument is controlled using gaze and head movement. A head tracking paradigm is used to control chord strumming, through a cheap ad-hoc built head tracker. Interaction methods and mappings are discussed, along with a series of experimental chord keys layouts, problems encountered and planned future developments.