Fugal Counterpoint

Interdependence of harmonically bound yet rhythmically independent voices, perfected by Bach.

Species counterpoint, codified in Johann Joseph Fux's Gradus ad Parnassum (1725), still anchors its teaching.
A fugue develops a single subject through staggered imitative entries in each voice.
Bach's The Art of Fugue explores one theme through canons and fugues of increasing complexity.