Reverberated Averages

"Reverberated Averages" is a series of experiments inspired by artist Jim Campbell's "Illuminated Averages" (2000-2009) . In "Illuminated Averages," Campbell averaged together all of the frames of a film to form a single composite image. I was intrigued by the way in which this process took a fundamentally temporal medium (film) and condensed away the dimension of time. It seemed to me that the same thing could be possible in the audio domain, so using the AlloSystem and Gamma multimedia c++ frameworks, I wrote a piece of software to condense a piece of music into its spectral average, resulting in a fixed, shimmering sonic fingerprint for the work. I call these artifacts "Reverberated Averages."

Take a listen to this one, for instance:

Can you guess what piece, or even genre of music it came from? Hover over this box to see the answer:

Bob Dylan, Blowin' in the Wind

If you had no clue, don't feel bad—I have yet to encounter someone who can guess these. However, once you know the source, can you here the bright twang of the harmonica on the right side? Can you hear the voice hovering around the center, on an average-sounding vowel? (I found it fascinating that all of the vocal formants averaged out to something like a schwa.) Try another:

Here's the answer:

Beethoven, Symphony No. 7, Allegretto

I averaged the left and right channels separately, so the instruments are actually spatialized as they were in the original recording. Here's one more for you:

...and the answer:

Jimi Hendrix, All Along the Watchtower

For this one, I actually made a video that flickers in response to the dynamic fluctuations of the original recording. In this way, after removing the role of time in the music, it is reintroduced as fragile apparition in the accompanying visual:

(The flickering image is, itself, an Campbell-style Illuminated Average of a video of Hendrix performing.)

Finally, I was amused to find that "All Star" by Smash Mouth sounded like this when I averaged it:

So basically, it's just noise. ;-) Of course, the real reason this happens is that the process of spectral averaging smears transients. So any noisy, percussive strikes, like a snare hit, just add a noise floor to the resulting average. I actually tried suppressing noisier frames, and got a more promising rendition of "All Star":

If you'd like to read up on the details of all of this, you can take a look at my short report on the process. Also take a look at Frozen Spring, an audiovisual installation that I created by applying this kind of process to a recording of the Rite of Spring.