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Battements et papillons, Jean-Pierre Gauthier

Musée d’art contemporain de Montréal Collection, A 06 2 I



Quantity Component Note
1 piano, quarter grand, Willis & Co.

A lid prop keeps the piano lid open.


Manufacturing Date: 1928

1 piano bench
with cover
4 motion detector, infrared Installed on the bench cover.
4 microcontroller, Basic Stamp Located on the bench’s lower surface.

The bench’s compartment contains the solenoids.


Voltage used: 15, 11, 18 and 24 V


15 V by default (used when the left motion detector is not activated); 11, 18 or 24 V (change the force of key depression).

1 interconnection bay, banana plugs with lateral grooves The relays (relay plates) are connected to the solenoids through the interconnection bay.
18 relays
The relays (relay plates) are located on the lower surface of the piano bench.
20 metal tension cables The piano and bench are connected by the tension cables.
1 motor Fastened under the piano.
5 transformer Placed under the piano.

wiring Power bar



Iconographic Technical Installation


The work is an interactive sound installation. In the centre of a dark room there is a piano and a bench covered in strips of aluminum tape, connected by metal rods and tension cables. When the visitor approaches the bench, motion detectors activate a mechanism that allows the piano keys to be depressed, producing random melodies. The piano ceases to play when the visitor is still.

The piano and the bench are connected by metal rods and tension cables.


Main components - piano

- Motor

- Transformers


Main components - bench

- Motion detectors

- Microcontrollers

- Solenoids

- Interconnection bay

- Relays


Four infrared motion detectors on the bench cover capture a visitor’s presence. These detectors activate four microcontrollers that respond to a programming code and send a signal to the relays. While three of these microcontrollers carry out the piano notes (keys), the fourth controls the voltage and activates a motor located under the instrument, triggering the movement of the sostenuto (or middle) pedal. The motor works unpredictably in one direction, then in the other, creating sound variations. The relays send the current to the solenoids, which are attached to the tension cables, allowing the keys to be depressed, producing random melodies. The notes cover two scales (D minor, D sharp/E flat) associated with various octaves. The instrument ceases to play when the visitor stops moving.


Motion detectors

The four motion detectors control, respectively, from left to right:

- The first: the motor and the force of key depression by changes in voltage (three different voltages: 11, 18 and 24 V);


- The three other detectors each control several notes and various combinations, as well as speed, which is fast at first, then slower:

- The second − eight notes with relay plates 1 to 7;

- The third − seven notes with relay plates 8 to 14;

- The fourth − five notes with relay plates 15 to 18.


Basic Stamp Microcontrollers

The Basic Stamp microcontrollers respond to the motion detectors and control the relays. They are independent from each other though execute the same program.



There is no maximum number of visitors permitted in the room but more than 15 visitors in a small room may reduce the work’s visibility.


1- The work must be installed in a dark room that measures at least 6.90 m x 5.22 m. Note: The walls and floor must be a dark colour. Carpet on the floor improves the acoustics.


2- It is important that the piano be tuned to 440 Hz. Piano tuning must wait until one or two days after installation so that the instrument can become stabilized (the bench must be taken apart to do so).


3- Open the crate containing the piano only from the front and remove it according to the installation instructions.


4- Screw in the motor for the sostenuto (middle) pedal under the piano.


5- Fasten the legs in the specified order and place the piano in the desired location.


6- Install the piano lid and prop it open using the lid prop.


7- Open the removable lid that covers the piano keyboard to uncover part of the keys.


8- Connect the bench to the piano using screwed in metal rods.


9- Fasten the end of the metal tension cables to the piano keys based on the numbering on the solenoids and the keys.


10- Connect the general electrical wire under the piano. It takes a minute before the program begins.


11- If necessary, test the tension cables by hand from the solenoids or with the current by using the banana plugs with lateral grooves.


12- The light must be shone directly above and below the piano lid, so that it can be reflected on the walls, without giving an impression of ambience lighting.



Dismantle the bench connections in the reverse order from setup.


Remove the piano legs based on the order indicated for dismantling.


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