A sympathetic piano by Gökhan Deneç

The electromagnets attached 2 mm. above the piano strings to create a sympathetic piano. © Gökhan Deneç

In Chapter Three of my book I discussed several early attempts of creating electric piano’s during the end of the nineteenth century. Often these efforts made use of electromagnets and feedback to keep the piano strings in vibration. The Neo Bechstein was one of the first commercially available results, but did not use any feedback anymore. During recent years new compositions and systems using electromagnets or tactile transducers and feedback for sound shaping and diffusing have been developed, for example by Per Blond, Andrew McPherson and Rama Gottfried (I’ll post about them in the future). Also Wave Train (1966) by David Behrman is related to these kinds of electric piano’s.

The hand-wounded electromagnets, with the permanent magnets inside the plastic reel.
The hand-wounded electromagnets, with the permanent magnets inside the plastic reel. © Gökhan Deneç

Gökhan Deneç has developed a sympathetic resonance system for a piano using electromagnets and feedback through its strings. He developed his own hand-wound transducers for this, using a simple but effective combination of wire, magnets and plastic reels. These electromagnets are placed in a grand piano and hung approximately 2 mm above the strings. The piano strings are attracted and repelled by the magnetic fields caused by these electromagnets. By sending the same signal through all electromagnets each piano string will start to vibrate, depending on how much its partial tones relate to the spectrum of the signal sent through the electromagnets.  A contact microphone (a model similar to an AKG C-411) is attached to the soundboard of the piano. In between this microphone and array of electromagnets a Pure Data patch is controlling and shaping the signal to the electromagnets. As Gökhan explains:

”My first intention was to create feedback to excite the piano strings and then by manipulating it I would create textures. Then I decided to define some possible regions for feedback to occur by sending an initial sound and also accompany the feedback by these textures. Also, I have a filtering algorithm that keeps the feedback under control. […] The sound creation is realised in PureData; there is a generative algorithm that I designed to create a very specific type of sound world. […] What you hear in the video is the generated tones that are created to vibrate the piano strings and because of its nature, they are unique in their own time. I can not repeat the same sounds, there are tons of randomization going on to construct this generativeness.”

This sound processing is controlled by the amplitude of the feedback signal coming from the contact microphone. Gökhan created an algorithm which is generating clusters of ten pitches, relating to the number of our fingers. A detailed explanation about how this all functions can be found in his PhD research. His PhD is entitled Creating sound mass using live sound processing and feedback with sympathetic vibrating strings and was defended in 2015 at Istanbul Technical University.

Gökhan Deneç is continually developing this project, so if you are a composer or sound designer interested in this system and would like to experiment or even compose a piece for this, please feel invited to contact him!

The Pure Data patch with a ten pitch cluster.
The Pure Data patch with a ten pitch cluster. © Gökhan Deneç

Bandoneonbook by Hans W. Koch

Hans W. Koch performing Bandoneonbook for laptop
Hans W. Koch performs Bandoneonbook, using the acoustic feedback between the internal microphone and loudspeaker of the laptop.

In Bandoneonbook (2003) by Hans W. Koch the acoustic feedback between the small internal microphone and loudspeaker of a computer is played by opening and closing the laptop, similar to how one would play a bandoneon. Computer software (a MaxMSP patch) is controlled by the keyboard of the laptop and by pressing some keys the feedback will be filtered in different ways. A piece which can only be performed with a titanium-powerbook series of 2001!

InPutOut by Ute Wassermann

Loudspeaker dress by Ute Wassermann with two microphones
Ute Wassermann performing with her loudspeaker dress in 1989.

Working with a similar principle as in Windy Gong Ute Wassermann developed a kind of loudspeaker dress , through which her voice was sounding (see both pictures above from 1989).

In 2015 she composed a new piece called InPutOut using these loudspeaker dresses for Les Femmes Savantes (Andrea Neumann, Sabine Ercklentz, Ana Marie Rodriguez and Ute Wassermann are performing). The performers wear a loudspeaker connected to a metal plate.

Loudspeakers prepared with metal plates for Ute Wassermann's InPutOut
Microphones and loudspeakers used in InPutOut (2015) by Ute Wassermann.

Each performer also holds two microphones: one to send the sound of the voice to the metal plate loudspeaker, the other one to amplify either the voice directly or the metal plate, which is excited by the voice. The signal of the second microphone is amplified through a small PA system. Holding both microphones in front of the metal plate, a feedback between microphone and metal plate loudspeaker occurs, amplified by the second microphone, which is connected to the PA system. A clear example of this feedback through the metal plate can be heard at 5’00” in the video documenting the piece. The microphone movements in this piece reveal fantastic possibilities of voice colouring, sometimes reminding me of  ventriloquism.