During a demonstration of his musical instruments, Hans van Koolwijk posed the question to the most inquisitive child in the class: what were the small pieces of lead doing in the flutes? These lead knobs alter the sound waves in the flutes, resulting in a change of tone. It went too far to explain the theory of harmonics or about nodes and antinodes in wavelengths. But this led Van Koolwijk to his next idea: 'Imagine that you are just as big as the lead nodes and that you can stand inside the flute. That you can change the tone with your own body; how would that feel? This idea developed into this enormous upright 'flute', the Oer-Oorsprong. Inside this object you feel the violent ultrasounds, 'sound as matter'.
The fans built specifically for these flutes allow for subtle nuances in sound to occur. The long, relatively narrow flutes are easy `overblown', creating a beautiful range of harmonics. These harmonics are in principle exact multiples of the root. But on the inside these bamboo flutes are not straight, and all kinds of enrichments in pitch and timbre are generated. Thereby the sounds create two slightly off-pitch whistles giving a splendid, pulsating tone: interference. The computer-controlled composition is created to make it seem like these variations happen accidentally. These bass flutes form the basis of the exhibition; they specify the atmosphere upon entry, a blanket of warm sounds.