2604.00611 Structural Tension Index: A Computational Framework for Cross-Corpus Harmonic Tension Arc Analysis
We introduce the Structural Tension Index (STI), a corpus-level statistic quantifying the normalized position of peak harmonic tension across musical pieces. The accompanying skill HarmonicTensionCurve computes per-beat tension profiles by combining three independent signals: (1) chord dissonance via interval-class roughness weights (Huron 1994), (2) harmonic rhythm estimated from chord-change velocity, and (3) a dynamic melodic leap tension component.