Many modern textbooks on counterpoint explain the subject/answer relationship in baroque fugues in terms of contrasting keys, with the subject centred “in the tonic,” the answer “in the dominant.” Others describe this more neutrally as a matter of transposition from subject to answer. These descriptions are commonplace in modern accounts of fugue; however, it is worth remembering that fugue originated in a modally-oriented musical style. As music transitioned from modality towards tonality, vestiges of modal organization remained a significant aspect of the musical language of various composers. Consideration of latent modality in baroque music can inform our modern understanding of eighteenth-century contrapuntal techniques in general, and Bach’s fugues in particular.
This paper proposes that a Dorian middleground schema exists in many of Bach’s minor-key fugues, where the characteristic division of the Dorian mode into a species of fifth and a species of fourth resembles the pairing of structural linear progressions guiding the subject and answer in many minor-key fugue expositions. Following a critical review of prior Schenkerian writings on fugue, especially the work of William Renwick, I will present analyses of several expositions from Bach’s fugues, demonstrating structural characteristics of four subject/answer paradigms common in many minor-key fugues. The Dorian middleground schema pursued in this paper suggests a nuanced explanation of the subject/answer relationship in baroque fugues, based in modal thinking rather than abrupt modulation or routine transposition, and illustrates the persistent influence of seventeenth-century modal approaches to fugue on the music of Bach and his contemporaries.