2. Pre-Classical Sentiment
Rosen claims that in the early eighteenth century, the "Unity of Sentiment" governed the music. The only music that escaped this unity was the music based on improvisation (toccatas, fantasies...). But every other works used to have only one sentiment, one single affect for the whole piece. That's the reason why when an articulation appeared it had the power to shock. For instance, Bach rarely wrote articulations and, when he did it, it was especially astonishing.
However, as Rosen says, "the Unity of Sentiment did not entail a monotonous representation of the affective content but allowed for subtle inflections". Pre-Classical Music is constantly inflected by changes in the harmony or in the texture. Consequently, the "undulations of expressive intensity are extraordinary. They are, however, never exaggerated." This development of a basic sentiment would be the prophecy of the later music developments: "When composers learned to integrate the fantastic contrasts of Baroque improvisation within a complex and formal structure, the Unity of Sentiment lost out to a new art of dynamic contrast."