Synergistic tension among the music and lyrics of late-Romantic choral songs

Songs intimately combine two defining human capacities: music and language. As a song unfolds, interconnected musical and linguistic elements such as dissonant chords and evocative words combine to generate fluctuating patterns of tension and relaxation, with associated predictive expectations that shape aesthetic and emotional experiences. However, how these patterns integrate across both domains to produce a holistic sense of tension remains unexplored. We investigated this integration in a tension-rich subset of Western vocal music, late-Romantic art songs, hypothesising that tonal and semantic tension combine superadditively. Using a naturalistic listening paradigm, online participants rated tonal, semantic, and holistic tension in three selected songs. Results suggest that the musical dimension (tonal tension) plays a more prominent role than the linguistic one (semantic tension) in shaping overall affect. Music alone explained a greater proportion of variance in the holistic condition than did lyrics alone. A significant redundant-information component suggested an integration of music and lyrics under genre-specific rules, while a synergistic-information component indicated their combined effect exceeds the sum of their individual contributions. Though based on a specific tonal-poetic idiom, our findings illuminate how music and language might integrate during real-time listening, from the experiential perspective of tension. We discuss how both culture-specific and culture-invariant (universal) mechanisms may contribute to this process, offering insights into cross-domain aesthetic integration.