Signals Intelligence

Signals Intelligence has a double meaning. Signals intelligence is the surveillance and collection of electronic transmissions, and now constitutes the largest component of the American security apparatus. It is ominous and omnivorous. In the search for extra terrestrial life, we scan the heavens in search of a transmission from a distant planet. Were we to ever receive such a transmission, it would signal the presence of intelligence by being ordered—non-random—and yet we would have no way to determine it’s meaning. We would be able to only listen, and wonder.

Signals Intelligence explores the experience of hearing an electronic transmission in which order is clearly audible but the information density is too high for any human to parse. The experience is one of being made aware of that which is always just out of reach, just beyond comprehension. Two related algorithms are employed to generate melodic material using from one to six pitches. One algorithm generates a self-similar series which replicates itself when played at different speeds, in effect comprising a mensuration canon in compound melody. The second algorithm generates a self-similar series which is also non-retrogradable (identical when played in reverse order). In the solo version, the results are applied to six indefinitely pitched objects, while in the ensemble version these are mapped to shifting pitch sets and presented in combination with indefinitely pitched instruments.

For a discussion of the mathematics and procedures of composition, see the article “Mathematics, Automation and Intuition in Signals Intelligence for Percussion”, in Sonic Ideas 4:1 (2012). Print edition available from CMMAS. Read the paper on Academia.edu.

The solo version requires six objects of the same type, with indefinite pitch, organized in order of ascending pitch.

The ensemble version requires two sets of instruments like the solo version, three mallet instruments, and bass drum, kick drum and bell plate. Some of the parts may be doubled with different instruments, resulting in a larger ensemble.

For discussion of the instrumentation for the ensemble version, see the Interpreter’s Forum.

The ensemble version of Signals Intelligence was commissioned by the Duke University Department of Music for the Milestones 2002 Festival. The “virtuoso” solo version which combines the solo version with part 6 from the ensemble version was proposed by Kyle Forsthoff.

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Ensemble version
8.5×11 PDF score and parts set
$25

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Solo version
8.5×11 PDF score
$10

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‘Virtuoso’ solo version
8.5×11 PDF score
$10

All scores are published by 

(ASCAP) and © Christopher Adler (ASCAP)