'SK, a score for Sisters Akousmatica, is an investigation of mysterious broadcasts called The Silent Key on the longest terrestrial shortwave relay on earth.
'Radio: drag the dial across frequencies at any given time, any given place and you will hear a cacophony of sounds. Static, pops and crackles, whistles, the tap, tap tap of the universe going about its electromagnetic business. In between those sounds are stations: broadcasts that are music, news, chatter, cryptic messages and espionage. Stretching out around the world in a network of terrestrial communication, bouncing off the heaviside and landing back again to be collected by radio-listeners.'
Source: Publisher's blurb.