Massachusetts Geophonic – How it works

Massachusetts Geophonic is a performative interactive piece that uses data from the USGS Massachusetts geological map as a palette with which the performer can create music – music from geologic data.

Data

The map of Massachusetts shows various layers of geological data:

The check boxes in the upper right turn on or off the effect of each of these layers of data on the sound produced.

Loops

The four colored lines represent transects or paths through the map that you can move – either by dragging the endpoints or the entire line. Musically, they're loops with a playhead that travels along them over and over again. The geologic data under this playhead at any given time determines the sound that's produced. Generally, a playhead will play a note when it crosses a boundary into a new type or age of rock, but a playhead can also be set to sample the data underneath it at specific intervals so that it plays notes in a rhythmic pattern.

The Master Length determines how long the loops are – and hence how quickly the music repeats itself.

Each loop also has its own controls. There are four sets of controls, corresponding to the similarly colored loops. These allow you to

Below each of the control sections is information showing the bedrock type and some of its geologic attributes, as well as its age in “Millions of Years Ago” and what the surface covering is like in that area. You can click these text fields to google the term.

Timeline

Additionally, the piece displays bedrock age in the timeline at the bottom, with a colored bar corresponding to each loop on the map. Note that the time scale is not linear… some of these rocks are very, very old.

Data to Sound Mappings

The basic data mappings are as follows: