Threshold of Beauty is an interdisciplinary project I designed that fuses music with the sciences. As part of this project, I have collaborated with a number of organizations to bring new music to students and adults alike.
In previous posts about my Threshold of Beauty project, I spoke about guiding a classroom of students through some fascinating science experiments, discussing how to identify art, and even constructing a few analog synthesizers. All of these experiences offered a unique blending of music and science in a palpable and hopefully interesting way for the students. But when I was developing ideas for my artist residency in Minnesota, I knew that I wanted to give anyone involved in the project an opportunity to both learn and compose something completely on their own. So I set out to design an installation piece that might function as an inviting learning environment where participants could create music as they interacted and observed.
The resultant work is Field Lines, my largest installation piece to date. Constructing this substantial piece of equipment drew on a number of disciplines including physical design, carpentry (an occasional hobby of mine), circuit design, and coding. As alluded in the title, this piece focuses on the magnetic field. There are three sections of magnetic material, including magnetic sand, a compass array, and zinc-plated iron. Audiences are able to manipulate these materials with a magnet in the space below each case while infrared sensors pick up their movement. The sensors send that information to an Arduino board, which then creates unique music for each section. Check out a few of the pictures below to get a sense of how all this came together.
Once I had finished the construction, it was time to test the piece out in the real world. And I was thankful to have two museum partners in Minnesota who were excited to present Field Lines. It was premiered at the Bakken Museum to a mostly adult crowd as part of their Current Affair Event in March. I ran into a few kinks, which I was subsequently able to solve, but for the most part I was able to enjoy meeting with the curious audience and seeing how they interacted with the musical and physical materials. And since then, the piece has found a home at the Works Museum, which caters to elementary age students. There it has been integrated into their “Sensor Zone” exhibit. Somewhere around a hundred kids interact with the installation each day and many have really seemed to enjoy the experience from what I’ve seen. Though I think if I ever get the opportunity to build another piece for a children’s museum, I might try to design something even more visual to combat some of the shorter attention spans.
Now for any who may be interested I am going to delve into the electronics a bit, all others will likely want to skip below to see/hear the piece in action! The instrument is powered by an Arduino Mega 2560 microcontroller, which I used because of its 16 analog inputs. 9 of those inputs are occupied by Sharp infrared distance sensors, 3 at the back of each section of the instrument to pick up the movement of the audience. These sensors are fairly sturdy, fairly accurate, and quite unfairly noisy. I was eventually able to significantly decrease the noise with several very large capacitors between the positive and ground rails of my circuit.
The musical aspects of the instrument are powered by the Arduino board and the recently released Mozzi audio library. This is a terrific “almost 9-bit” open-source library for the arduino platform, which is greatly superior to the built-in tone() function. Having said that, the library comes with its limitations (or at least it did, it is being improved by leaps and bounds everyday). The main issue being a high and continuous ringing pitch, which seems to be derived from the sample rate (16kHz). After a bit of digging, however, I discovered that this issue can be solved with a small electronic circuit. The circuit combines a low pass filter and a twin-t notch filter in series and you can find the schematic floating around on the Mozzi website. And that covers the basics of the electronics. Watch the video below to see the final product!