In 1973 Boguslaw Schaeffer composed the “Synthistory” commissioned by the Belgrade radio station. He needed only 55 hours to finish this electronic music piece, because the radio station owned a very rare synthesizer Synthi 100. Working on it he could express the very precise construction of the piece which he had been carrying in his head for years. Lukasz Szalankiewicz created his own interpretation of “Synthistory”. His “Signalstory” is a sonic performance, in which a main source of sounds is an magnetic ﬁeld controlled and detected by the walkmans. An important thing is an interference between different objects and high frequency, among which voices of ” unknow ” are hearable like in the EVP technique – imitated and real ones.