EN
From 1643, about 20 years after his arrival in Poland where he became maestro di cappella in Warsaw, Marco Scacchi began to publish polemical texts, directed mainly towards German-speaking musicians, in which he familiarized readers with some principles of musical compositions. The article describes the confrontation between two theoretical positions: the Italian one, represented by Scacchi, and the north German one, personified by the organist from Gdansk, Paul Siefert, which originated as an almost purely personal friction, yet with time, it became a polemic with much wider reception. Although Scacchi's theoretical writings do not constitute a fully cohesive body of knowledge, their chronological analysis reveals a perceptible evolution of the author's views, his classification of musical styles being its most original element.