 The tape recording of this first microphony experiment was for me a discovery of the greatest importance.We had made no agreement about what the other would do; I used some of the implements that lay to hand as the mood took me, and at the same time I probed the surface of the tamtam with the microphone, as a doctor probes a body with a stethoscope; Spek also reacted spontaneously to what he heard as the result of our combined activity.