In 'pure' instrumental music, the strategies chosen by composers to create unity were responsive to the tenets of Romanticism... Even in the absence of an explicit program, motivic continuity created a kind of narrative coherence. Like the chief character in a novel, the 'fortunes' of the main motive—its development, variation, and encounters with other 'protagonists'—served as a source of constancy throughout the unfolding of the musical process.

Style and Music: Theory, History, and Ideology (1989), ISBN 0226521524