Invented in 1884 by the French engineer Philbert Maurice d’Ocagne, nomographs are graphical analogue calculating devices that allow the computation of linear or non-linear functions. Now superseded by computers and electronic calculators, these diagrams were once the preferred method for calculating solutions to practical problems when a few variables were already defined within a complex system. Ron Doerfler’s The Lost Art of Nomography is a good essay on the history of these charts, it also explains exactly how they work.

The musician/performer David Tudor used the term nomograph to describe a notation he created for the performance of John Cage’s Variations II – we might wonder if Cage ever used the term himself ? Cage created scores that not only bare an uncanny resemblance to nomography but also use a nomographic process to generate musical events within his partially deterministic musical space-time. The projection of lines into two and three-dimensional space, and their resulting intersections with other lines and points, were used to define musical events in his works of the 1950’s such as Concert for Piano and Orchestra [1958].