This sound of theremin artist Anthony Ptak. Liner notes: Difference Frequencies (2015) [5:00] This computer music work concentrates on difference frequencies as a carrier of information. We listen to the world as a system of associative indices. The acoustics of the physics world are generated sine wave partials, synthetically generated phenomena. Sound is a virtual axis that occupies and transforms space. The heterophony of the score is navigation. All sonic materials generated, performed, and assembled by the composer. - AJ Ptak