The Induction Connection – a Musical Research Residency at IRCAM

The IRCAM project subsection of this site is divided into the following parts:

  • Overview (this page),
  • Phase 1a – Measurements and testing,
  • Phase 1b – Piano modeling,
  • Phase 2 – Implementation of the Induction Connection in Modalys,
  • Induction Examples – Experiments with various parameters.

In the spring of 2013 I conducted a 5-month Musical Research Residency (now called the Artistic Research Residency) at IRCAM in Paris. My research proposal was as follows:

“Building on my research and compositional activity involving the EMPP, I propose to work primarily with the Instrumental Acoustics Team to develop a physical model of the coupling between a resonator (initially a piano string) and an electromagnet. After an initial exploratory phase, this coupling would then be implemented in Modalys. Such an implementation has three primary functions: 1) as a sound source in its own right, capable of generating interesting and unusual sonorities, 2) to facilitate research on string properties under the influence of alternate sources of excitation, or more specifically on the effects of electromagnets on strings, and 3) to allow for ease of testing, experimentation, and composition with the Electromagnetically-Prepared Piano without need of its physical presence.”

A pdf of full text of the proposal can be accessed here.

Over the course of the project I worked most closely with Joël Bensoam and Robert Piéchaud, though I received help from many. Joël’s primary role was to create the algorithm used to determine the force exerted by an electromagnet on a vibrating body (induction). Robert’s primary role was to code this algorithm into Modalys as the Induction Connection. My primary role was to conduct measurement tests on the physical implementation of the device, and write code to test the resulting algorithm in Modalys for comparison.

The project unfolded in two distinct phases.

Phase 1 – measurements, testing, and piano modeling. This phase involved:

  • Acoustic measurement tests of an electromagnet positioned over a simplified piano string monochord (eliminating the piano bridge, soundboard, additional strings, etc) (Per),
  • Acoustic measurement tests of electromagnets positioned in a grand piano (i.e. the full EMPP device), first isolating a single string, then using all 12 (Per),
  • Study of the acoustics of the piano, and construction of a viable piano model within Modalys (Per, with essential assistance from Adrien Mamou-Mani and René Caussé),
  • Study of existing literature on the physics of induction, and creation of an initial algorithm modeling this interaction (Joël).

Phase 2 – implementation of the Induction Connection in Modalys. This phase involved:

  • Adding our implementation of the Induction Connection to the code base of Modalys (Robert),
  • Testing the resulting build (Per, Robert),
  • Refining the algorithm based on the results (Joël),
  • Updating the Modalys documentation to reflect the new connection type (Per, Robert).

The final outcome was the addition of a new type of connection to Modalys: the Induction Connection (see documentation). IRCAM has made available a video of our final presentation (Note that Joël’s part is in French, while Robert’s and mine are in English).

Continue on to Phase 1a – Measurement