A virtual pendulum, simulated on a computer by a damped harmonic oscillator, crosses zones whose boundaries are defined interactively by the user. Each zone is programmed to trigger a sonic event which is variable in intensity, timbre and / or frequency, depending on the speed of the pendulum when it enters the zone.

The composer plays this virtual instrument with potentiometers. He modifies in real-time the mass, the stiffness constant, and the damping factor, and may also add various external disturbances. All of these forces interact and continuously modify the aspect, the speed and the amplitude of the movement, either generating pseudo-repetitive sequences or disrupting the equilibrium.

There is a sombre atmosphere, populated with little, organic-like virtual beings which resist the swinging motion and disrupt its regularity. This matter offers itself up for periodic transformation and distortion, colours are revealed and recombine, chimeras emerge from the nothingness and invite us to follow their hypnotic oscillation…

Disappearance, appearance, proliferation. Moans can be heard… are they calls? Responses? Is collapse inevitable? Is there something which could slow it down or stop it? Accident or destiny, uncertainty reigns as absolute master. There is no point in resisting…

— Todor Todoroff [English translation: Stephanie Moore, i-19]

Rupture d’équilibre [Rupture of Balance] was realized in 1993 at the ARTeM (Art, recherche, technologie et musique [Art, Research, Technology, and Music]) studio in Brussels (Belgium). It was remixed in 1995 and entirely revised in 1997. This latter definitive version premiered on May 21, 1997 during the concert Discoveries XXVI in Aberdeen (Scotland, UK). Rupture d’équilibre was a finalist in the Concurso Internacional de Música Eletroacústica de São Paulo (CIMESP ’95, Brazil) and the definitive version was a finalist in the Musica Nova 2000 International Competition of Electroacoustic Music (Prague, Czech Republic).

Premiere

• May 21, 1997, Premiere of the final version: Discoveries: Discoveries XXVI, Northern College – Studio HG19, Aberdeen (Scotland, UK)