Gravity Harps, Version 2

source: highlike

Work: These are the second version of The Gravity Harps, which use the Earth’s gravity to create musical rhythms and patterns. I originally designed and developed them in collaboration with Björk, who was inspired by the Foucault pendulum and wanted to play music using gravity. They are each comprised of a pendulum and a round acoustic harp. The carefully balanced pendulums swing with metronomic precision, collectively able to create a variety of rhythms. As each harp passes through the bottom of the pendulum’s swing, it is plucked by a mechanical extension of the pendulum. The harps can rotate under computer control to cause different strings to be played. In this way, many musical patterns can be created using rhythms set by gravity.
Photographer: Andy Cavatorta
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source: andycavatorta

The Gravity Harps are the final version of the pendulum instrument and are featured in Bjork’s current Biophilia show in Manchester UK.

The idea was born during a slightly tense meeting after the Manchester parameters had changed. The Pendulum Ring was out for now. We needed a new idea. We had about 4 weeks and the clock was ticking. I drew this idea on a scrap of paper. The Gravity Ring was originally envisioned for Bjork’s Biophilia project. I met her and Michel Gondry at the MIT Media Lab when they were looking for people and inspirations for a 3D film based on Bjork’s Biophilia concepts.

Concept 1
We discussed a lot of ideas in the first meeting. The first challenge was to play one of her lovely new songs with carefully synchronized pendulums. I tried to find a simple way to play the irregular pattern of the new song Solstice. This way wouldn’t work live. But for film it would be just fine:

Concept 2
Next, it was time to make some music. It would have been easy to place instruments on the floor and pluckers on the pendulums. But I wanted each to be self-contained. The first physical prototype worked out really well.

Concept 3
The song is called Solstice, so I wrapped the line of pendulums into a circle, to create patterns that echo celestial cycles.

This would have looked amazing on camera. I still hope this idea gets used someday.

At this point I thought I knew what I was doing. So I worked with Dan Paluska and Bill Washabaugh to test out a mechanical drive system for pendulums. This it the prototype that taught us that you can’t fool the eye. It was going to have to be real, free-swinging pendulums.

Bill’s early CAD drawings reflected an original, simpler design in which each pendulum could play a number of different notes. This would give the instrument musical flexibility to play the structurally complex song with as few as 16 pendulums.

Concept 4
But Björk wanted each pendulum to play only one note, so that the patterns of motion echoed the patterns of the song. An instrument shaped like a song! I liked it. So I wrote this simulator to figure out how to do it. Click the image below to open it. Marina Porter created a series of prototype harps made from fiberglass, spruce and aluminum.