Naming the Shape of a Loudness: A Form Codex for Field Material

A loudness envelope always admits a best-fitting curve, and a best fit always has a sign; a rule that reads that sign unconditionally will name a dome in pure noise. This paper specifies a rule that does not, and freezes it as the Form Codex for Field Material, version 1.0. The envelope is cut into segments, a quadratic is fitted to each, and the segment is named only if the amplitude of that curve clears twice the standard deviation of its own residual: below that bar it is DROITE, straight, whatever the sign of its curvature. Four rules tried and withdrawn are recorded, including two that manufactured shape from noise on every recording tested. On the executions to date, eight segments in eighteen carry no nameable shape — forty-four per cent, reported rather than resolved. The paper's own result is that this refusal is the instrument: DROITE is an answer and not a failure, and the rule can give it only because the threshold was fixed before the material was seen. Where the rhythm codex reports the distance between its output and the given as a number, this one uses that distance — the residual of its own fit — as a threshold instead, trading a reportable number for the capacity to decline.