Granular Graph

ABSTRACT

Granular Graph II: The tank and the pendulum is an audio-visual interactive instrument about musical gesture and its notation. The idea is inspired by a pendulum-based scientific instrument called Harmonograph. In its simplest version, two pendulums are suspended through holes in a table. The swinging pendulums cause an attached pen to move, thus creating a curvaceous geometric image that represents harmonies and intervals in musical scales. Granular Graph II: The tank and the pendulum not only re-appropriates the idea of a mechanism by inviting audiences to form a living pendulum, but uses water to graph the amount of energy, effort and tension involved in causing the sounds. According to its original design, two pendulums are arranged in a perpendicular relationship. While one pendulum keeps the distance between the pivot and the center of mass (in this case, weight) constant, the other pendulum changes the position of the weight to create different lengths, resulting in different frequencies. In the current version, any visitor can play the instrument by sitting or standing on one of two swings. The sitting swing functions as the constant length pendulum, while the standing swing changes the length of the pendulum by changing the center of mass, depending on the actions of the visitors. The resulting pendular movements alter the waterflow in a tank located above the beam, generating not only a vibrating pattern but also sounds. These sounds result from the combination of the two vibrations, just like two notes playing in unison. The image of the water vibrations is shown via video projection. The sounds and images can be regarded as forms of dynamic notation that graphically and kinetically represent the audience's gesture and energy expenditure.