The LIDAR Harp - the development and evaluation of a new MIDI controller

This paper describes the development and evaluation of a MIDI controller inspired by the Theremin and Harp. It consists of twelve LIDAR sensors in a row that trigger MIDI note messages dependent on the key chosen. The height of the hand above the sensor allows for expression in the form of velocity (volume) information or any Continuous Controller (CC) parameter that the user might choose. The design process was largely inspired by a prototyping approach and followed a number of iterations. The controller was evaluated using the System Usability Scale, comparing the device with a version of the device with the height control removed as well as a Korg Kaossilator. 24 subjects evaluated it with 50% of these being musicians. It performed well against the Kaossilator in terms of usability, however opinion was divided between the two modes of play on the controller. This could be due to using one dimension of control (No CC control with height of hand) which allows for polyphonic playing, whereas with two dimensions the controller acts monophonically. Immediate future work includes using a faster microcontroller to reduce latency. Additional areas to be explored include optimisation of musical expression from a user perspective, by facilitating the adjustment of the maximum range of the sensors, inversion of the height control and exploring features such as pitch bend, that would also allow the use of accidental notes in the scales.