Arousal is one of the six core dimensions in SongScore's Sonic DNA fingerprint, measuring how activating or calming a track feels on a 0-to-1 scale. It is related to but meaningfully distinct from Energy — a track can have high Arousal with moderate Energy (a tense, quiet string section) or moderate Arousal with high Energy (a repetitive, loud electronic loop that becomes hypnotic rather than exciting).
Arousal is calculated from spectral variation (how much the frequency profile changes moment to moment — high variation increases arousal), rhythmic complexity (syncopation, irregular rhythmic patterns increase arousal), harmonic tension (unresolved chord progressions, suspended chords, and dissonance increase arousal), and dynamic unpredictability (sudden changes in loudness or texture increase arousal by keeping the listener's attention engaged).
Arousal is particularly important for streaming performance because it drives two key listener behaviours: attention retention (mid-to-high arousal tracks hold listener attention better) and repeat listening (very high arousal can be fatiguing, reducing repeat plays). SongScore uses Arousal alongside Valence to map each track onto the Circumplex Model of Affect — the two-dimensional emotional space that drives music recommendation on every major streaming platform.