Keywords
Fluid Media; Tactile Interface; Installation; Water Sensors; Interactive Art

Abstract

Tangible Sound is a musical instrument with a novel user interface that uses fluid water. Fluid water is a suitable interface for performing flowing sound and music because fluid and sound have common characteristics. For example, both media change shape over time and thus cannot be grasped. We created a live and hands-on installation for Tangible Sound. As water, among the various fluids, is frequently used in daily life as an essential resource, a musical
instrument using water will be intuitively appealing and become an amenity of the future. Although there are many installations and interactive artworks that use water, they do not exploit the potential for water to be used as a musical medium. This installation aims to find practical uses of fluid media for musical instruments.    In addition, we have developed a method of sensing the volume of water flow corresponding to enjoyment of the music. For judgement a user's actions we use the changes in the upper flow from the faucet and the lower flows toward the drains as well as the difference between two kinds of values. This configulation leads to a novel concept of "Source and Drains" for a programmable musical instrument. The concept is also applicable to traditional wind instruments. "Tangible Sound" is created as a novel musical instrument that uses water as input media based on this concept.    For measuring the upper flow, we use the radius of the flow under the faucet by sensing resistance of water with nichrome wires. The lower flow is also measured by resistance of the lower water. Funnels are prepared as drains, and in each drain we installed nichrome wires for sensing water level, which is used to measure the volume of lower flow. The level is raised when the volume exceeds the draining capacity of the funnel.    We investigated two kinds of software configurations for the above "Tangible Sound" hardware. One uses the choice of drains for input selection of acoustic elements. When the user touches the water flow, the water sound is continuously filtered to resonant frequencies of a musical harmony. The other configuration uses direct input of musical elements with MIDI signal control. The user can control four kinds of harmonies by choosing funnels of different heights. MIDI note numbers (limited by chord) and note on-off signals are made by the water levels of the funnels, and velocity and duration signals are controlled by the upper flow faucet. These software applications run on the MAX/MSP programming language.
We will demonstrate the live installation to provide participants with hands-on experiences. The concept of "Tangible Sound" will become clearer when people touch water and play music with the fluid media.