Dani Oore “Polygraph Music: Poly- Rhythm and Truth in the Snowden Trailer,” with Carol Vernallis “Tracing the Asset: Humanistic and Quantitative Approaches to Cybercrime Film Trailers,” in Society for Media Studies Conference, Toronto, 2018.



RHYTHM in the SNOWDEN MICROTRAILER (0m00s-0m04.5s)

We can hear the steady pulse in the audio. What about the visual rhythm? Here is a sonification of one possible interpretation of the visual rhythm:

Analysing the timing relationship between the steady sonic pulse and the unpredictably unfurling images:

    In the above visual, the audio waveform and video stills from the microtrailer (0m00s-0m04s) are presented in three chunks (for ease of space). Each chunk has three rows of information:

  • Top rows show video stills beginning on sonic off-beats (lowest audio waveform dB level)
  • Middle rows show video  stills beginning on sonic on-beats (highest audio waveform dB level)
  • Bottom rows show audio waveform (left channel only for simplicity)

Sonic pulses (peak acoustic onset represented by “•”) and concomitant image stills:
In the above chart, parenthesized words indicate images whose onset is more ambiguous (e.g. partially crossfaded with previous image or sharp cut that occurs just before a sounding pulse)

Microtrailer polyrhythm: the relationship between the steady pulse sound and the syncopated visual images can be represented in a various notations and with various subjective interpretations (of the cross-fades)…

a different subjective rhythm interpretation and notation…



Diagram showing the complexity of the relationships between the many tempo (and tonality) changes in the Snowden trailer. I imagine these sudden and unpredictable fluctuations to be like flutters registered in Snowden’s polygraph test. Elusive truth.

  • Explanation of diagram:
  • The row of numbers along the bottom (180 – 0 – 180 – 200 – 164 – 40 – 130 – 124 – 251) gives the sequence of tempos (in beats per minute, bpm).
  • Each curving line connects one tempo to every other tempo.  There are seven different tempos (not including 0) so each one has six lines connecting it to each of the other tempos. Each of these connections between two tempos is labeled with the ratio that most closely describes the temporal relationship between the given two tempos. For example, the left corner has 180 bpm connected to 200 bpm. This connection is labeled ~10:9, because approximately 10 beats at 180 bpm occur in the time of 9 beats at 200 bpm.
  • It can be seen that most of the ratios are complex (e.g. 10:9, 12:5, 15:16) rather than simple (e.g. 2:1).
    The approximation of the ratios (~) reflects that the given ratio is merely the closest whole number ratio I could find to produce the tempo change actually experienced. Ratios that appear simple (e.g. 2:1, or 1:4) are in fact complex and tense because they are not quite resolved as a simple gestalt.
  • The significance of these two items —the complex ratios and the non-integer ratio approximations—  is that they provide a quantitative measure of just how unpredictable the tempo changes in the Snowden trailer soundtrack consistently are.  They do not change steadily or by a simple factor (of 2). This is one way in which the Snowden trailer thwarts our expectations, and has us contending with the elusiveness of truth.