We built the MetaMuse system to explore the role that metaphor plays in developing expressive devices. MetaMuse is a prop-based system that uses the metaphor of rainfall to make the process of granular synthesis understandable. With MetaMuse we introduce a two-axis transparency framework that can be used as a predictor of the expressivity of musical devices. Metaphor depends on a literature, which forms the basis for making transparent device mappings. On this page you will find a brief introduction to MetaMuse, along with links to several papers with more detailed discussions of the system. You will also find downloads for three libraries that were designed and implemented for the project to parse data from devices on the serial port.

MetaMuse is a prop-based instrument that uses the metaphor of rainfall to make the process of granular synthesis understandable. The sound of rainfall in nature comes from a process very similar to that of granular synthesis: short, discrete sound samples layered and overlapped to create a gestalt. MetaMuse was built to demonstrate the principle of ``transparency,'' a concept intended to facilitate the creation of expressive instruments.

We identify transparency as a quality of mappings, where a mapping is the connection between the input interface and output interface of a device. Similar to control intimacy, transparency provides an indication of the psychophysiological distance, in the minds of the player and the audience, between the input and output of a device mapping. The more transparent the mapping is, the more expressive the device can be. The degrees of mapping transparency for the player and audience form orthogonal axes of a graph into which devices can be placed. The position of a device in the graph acts as an indicator of its expected expressivity. New technologies, often being poorly understood, tend to sit in the opaque corner of the graph. (For further discussion of the concept of transparency, see the Organised Sound publication below.) Metaphor is one technique to facilitate moving from an opaque mapping to a transparent mapping. Metaphor enables instrument designers, players, and audience members to refer to cultural bases or elements that are ``common knowledge,'' which we call literature. By grounding a mapping in the literature, it is made transparent to all parties. Metaphor restricts and defines the mapping of a new device. Through metaphor, transparency increases, making the device more expressive.

MetaMuse uses the metaphor of a falling particle impacting a surface and creating a sound as an interface to a granular synthesis engine. This choice of metaphor defines a class of instruments in the same way that choosing to excite a string with a bow identifies the class of traditional instruments that includes cello and violin. Props are used to control the particle model; the mapping of prop positions into physical model parameters and then into granular synthesis parameters defines the specific instrument within the class. Two props are used in MetaMuse: a watering can and a flat palette. The watering can affords the creation of particles through the motion of pouring, and acts as real-world pouring experience would lead the user to expect. The palette creates a surface on which the particles can impact. Once again natural parameters are used; for example, the velocity of the particle on impact affects the volume of the resultant sound.