Venetian Clouds and Newtonian Optics

By common consent, modal mixture (the pairing of the major and minor keys over the same tonic) is acknowledged as a fundamental resource of mature harmonic tonality that acquired primary syntactic role and formal importance only in the late 18th century. This article aims to disprove this view by: 1) showing that modal mixture had been extensively employed by North-Italian composers already at the turn of the 17th to the 18th century; 2) reviewing these composers’ use of modal polarity through the lens of contemporaneous scientific theories and artistic practices. Rhetorical and grammatical aspects of binary oppositions and modal transportability of parallel major and minor keys are analyzed in the music of Venetian composers (Antonio Vivaldi, Tomaso Albinoni, Antonio Caldara, Benedetto Marcello). Their innovative treatment of modal mixture corresponds with the simultaneously emerging aesthetics and pictorial imagery of clouds and the new chiaroscuro techniques in Venetian art (Giovanni Battista Tiepolo, Sebastiano Ricci, Giambattista Pittoni, Francesco Guardi). I suggest a semantic approach to modal mixture through the lens of “Venetian” clouds with their morphological function of reflecting light and reciprocating colours between objects. This link between Venetian music and art is further considered through the prism of contemporaneous optical theories, as stimulated by Isaac Newton and advanced by his translators and exegetes in the Veneto, giving special scrutiny to Francesco Algarotti’s Il Newtonianismo per le Dame (1737). Algarotti widely addressed Newton’s theories of reflected light and of the transparency and opacity of objects, explaining their relevance and applying them to various cultural phenomena. The exploration of modal mixture in music thus mirrors the all-embracing impact of new scientific theories on the intellectual climate of the Veneto.