I’ve been coming to Northwest Arkansas for the last four years to play in the Artosphere Festival. Every time I visit, one of my favorite things to do is visit Crystal Bridges and spend time in the James Turrell Skyspace The Way of Color.
One of the most interesting things about James Turrell’s work is the way it affects our perception of light and time. The former is achieved by combining natural light (from the oculus) and synthetic light (the LED light display). When I first began to think about a work for the Skyspace, I thought it would be interesting to explore this idea of natural vs. synthetic, but with sound.
The Way of Timbre is a sonic interpretation of the Skyspace. It is made of two components: synthetic sound (mapped from the LED light display inside the Skyspace) and acoustic sound (reflecting the changing natural light from the oculus). Combined, the two parts produce interesting aural effects that complement the visual experience of the Skyspace.
In short: LED lights —> synthetic sound (sine waves) Natural light —> acoustic sound (trombones and didgeridoos) The first main component of the piece is made from pure sine waves. Sine waves are much like the building blocks of music —many sounds can be made from a combination of pure sine waves. Here is what a pure sine wave looks like:
And here is what a pure sine wave sounds like:
Pure sine waves are analogous to primary colors —when mixed together, they produce rich dynamic timbres and textures. Sounds that are very resonant (like a really great opera singer or strong brass players) are made of many layers of these waves. The softer tones above the lowest note of the spectrum are called harmonics.
Sine waves also have interesting properties. For instance, when you play two sine waves that are just slightly out of tune with one another in separate speakers, they produce a barely perceptible sweeping effect. This is because they gradually cancel each other out when they move in and out of phase.
Here is what this sounds like (best with medium sized speakers —laptop speakers will not work very well).
It sounds like the waves are changing pitch and volume, but in reality it is just two constant tones. This is an effect I use throughout the piece to give the sound a slight shimmer, similar to the visual effects of the LED lights.
Besides sine waves, the other components of this piece are acoustic instruments: trombones and didgeridoos. Unlike pure sine waves, which are made of one frequency, trombones and didgeridoos are very resonant and are made of a spectrum of sound colors.
In short, sine waves are like primary colors (one color), and trombones are like white light.
One of the interesting things about resonant sounds is that it’s possible to isolate the harmonics above the fundamental. This is somewhat like using a prism to isolate the colors of a rainbow with white light. This can be done with a mute on the trombone.
These synthetic sounds and acoustic sounds mix in real time to create a shimmering, slowly oscillating fabric of sound. Here is a short clip of this combination:
They day of the Solstice, we’ll have an interactive booth where audience members can play with sine waves and learn how to make their own didgeridoos from PVC pipe. Later, we’ll perform The Way of Timbre at sunset, around 8:30 pm.
I hope you’ll join us at Crystal Bridges Museum of American Art that day for the premiere of this new piece!