Fugue answer — tonal vs. real, and the modulating-answer case

A fugal answer is a REAL answer (exact transposition of the subject up a perfect 5th, or down a perfect 4th) UNLESS: (1) the subject's OPENING note is ^5 of the home key — the answer's opening note must be ^1 rather than the ^2 a literal up-a-5th transposition would produce, avoiding premature dominant-key establishment; or (2) the subject itself modulates to the dominant within its own span — the answer must correspondingly modulate back toward the tonic for the portion answering the subject's dominant-key material.

A subject beginning on ^5 answered with a literal, unadjusted up-a-5th transposition (landing the answer's first note on ^2 instead of ^1) — the single most common tonal-answer error.

Standard fugue pedagogy (the tonal-answer rule traces to Gedalge's Traité de la fugue, universally taught in modern fugue courses); outside Gould/Read/Ross/Stone's scope, flagged as such, directly relevant to Gradus's fugue curriculum.

This rule needs the notated content and the rendered result together — the score says what should happen, the page says whether it did.