Live recording by Sond’Ar-te Electric Ensemble – Sílvia Cancela (fl.), Luís Gomes (, Joana Gama (pno.), Suzanna Lidegran (vln.), Nelson Ferreira (vlc.) and Guillaume Bourgogne (conductor) · at Goethe-Institut Portugal, October 2012


pendulum, for flute, bass clarinet, piano, violin, violoncello, realtime video and electronics, is a study on dynamic spatialisation. It was commissioned by Sond’Ar-te Electric Ensemble in 2012. Digital models of physical elements are used to generate both spatial and musical gestures, being represented during the performance in a video controlled in realtime by the pianist. These models include simple pendulums, pendulum waves, multi-body gravitational systems and elastic systems.

The main elements explored in pendulum are:

  1. the symbiosis between musical gesture and spatial gesture, achieved by the generation of the musical material from the spatialisation, thus inverting the traditional order of execution;
  2. the hypothesis that the perception of movement, both visual and auditory, is conditioned by the mental representation of an intuitive physics — an explanation for phenomena such as the representational momentum, amongst others — is explored through the action of easily recognisable forces that drive the musical and spatial gestures;
  3. the hypothesis that patterns emerge in the visual movements can be related to patterns that emerge in sound not only by their simultaneity and common fate, but also by the development in one domain of expectations built in the other.

The complete score of pendulum is available here and the Max patch for public presentations of the fixed-media version of the piece (both for concert and installation purposes) is available here.


By practical reasons, related not only to the characteristics of the auditorium of the première, but also to the need of using the same loudspeaker setup for other pieces in the same concert, some limitations were imposed from the start:

  1. the piano would be on stage;
  2. the video projection would be limited to a vertical plane behind and above the piano;
  3. the loudspeaker setup would be horizontal, concentric and regular around the audience.

Above, one can see the stage plan with the loudspeaker setup — driven by spatium, a project developed in parallel to pendulum — and the location of the instruments.

There was the potential for a spatial incoherence between the vertical plane on stage of the visual representation and the horizontal plane around the audience of the sound diffusion. It was thus decided that:

  1. the video would be primarily articulated with the piano, due to their physical proximity;
  2. the piece would be divided in sections by the exploration, on one hand, of movements from one side of the room to the other (i.e., following the video projection), and, on the other hand, of circular movements around the audience (i.e., following the sound diffusion);
  3. a silent movement of the pivot point would mark the transition between sections;
  4. the remaining instruments would be divided between both sides of the audience, in order to allow the spatialisation of both lateral movements (from flute & violoncello, on the left, to violin & bass clarinet, on the right, and vice-versa) and circular movements (e.g., piano, violin, bass clarinet, loudspeakers in the back, violoncello, flute, and piano).

A CD recording of pendulum, by Sond’Ar-te Electric Ensemble, is available at Miso Records. An article written in 2013 about the piece in the journal Sonic Ideas is available here. A radio program about the piece (in Portuguese) is available here.