Midfourth

Midfourth is a term that appears in niche theoretical discussions without a single, widely accepted definition. It is formed from mid and fourth, implying a focus on a central or median sense of the interval of a fourth within a musical or theoretical context.

In music theory, some writers use midfourth to describe a conceptual zone or principle around the interval of a fourth that organizes harmony or melody in quartal or polyphonic textures. It may be used to describe voice-leading patterns that place a fourth relationship near the center of a progression, or to discuss how quartal chords foreground fourth-interval sonorities rather than traditional triadic function. Because usage is informal, the term often depends on the author’s framework and is not standardized.

Beyond music, the term has appeared in interdisciplinary discussions as a descriptive label for centrality around a fourth relation in other systems, though such uses are even more variable and informal.

As of now, midfourth has no fixed definition in major reference works. It is typically encountered in online discussions, pedagogical notes, and experimental analyses. See also: quartal harmony, fourth interval, voice leading.