Microtonal F tuba plus surround-sound system
A common way of visually representing harmonic relationships is by means of a three-dimensional diagram in which intervals based on the prime number 3 are aligned horizontally, those based on the prime number 5 are aligned vertically, and those based on the prime number 7 are aligned diagonally. The space between prime numbers 3 and 7, lying between the horizontal and diagonal axes, is therefore depicted as an ascending series of plateaus. Plateau Square explores the harmonic space implicit within one of these plateaus. Each of the four speakers of the quadraphonic sound system represents a corner of the plateau, and the microtonal tuba pitches are routed to the corresponding speaker(s) by means of sensors attached to the valves, which enable the signal to be routed differently according to which valve combination is being depressed.