After weeks of hard work, Hill will be presented at the Center for Computer Research in Music and Acoustics (CCRMA) at Stanford University on December 10, 2014 at 12:00 PM. At this presentation, Hill will be paired with an original poem, written by myself, called "Crescendo".
Hill is a musical and visual accompaniment for spoken word poetry, written in C++ using OpenGL. Hill can read in a JSON score which provides poem text, audio input, camera locations, text movements, and timing for each line of the poem. The score specifies an audio input file. Hill will iteratively apply the Sukothai effect on this audio file depending on how far away the camera is from the middle of the scene.
I experimented with trying to have the performer live-record the audio during performance. This turned out to be very difficult and not elegant at all. So I looked at other options. There is an effect (and composition) by Carl Stone called Sukothai. It was introduced to me by Jonathan Abel. Sukothai does a sort of musical zooming out on a piece of sound by randomly delaying some mono audio signal by the same amount forward and backward and outputting those delayed signals to stereo audio channels. If we take that output, add it back to mono, and iterate, we can get a greater effect. After about 10 or more iterations, the effect becomes this beautiful musical envelope of sorts that really fit the aesthetic of Hill.
Furthermore, Sukothai assumes a uniform distribution of random delays between the longest amount of delay you'd prefer and it's negative. With each iteration, the randomness of the delay convolves with itself, just due to the nature of the effect. So, at two iterations, our random number distribution is a Bartlett function, and at some number of iterations, the distribution approaches a Gaussian curve (see: the central limit theorem). This Gaussian curve, shown below, is a visible representation of the "hill", and the Sukothai effect creates an audible "hill of sound" that works with the aesthetic. Jonathan and I were very happy with this mathematical serendipity.