A fugue (from Latin fuga — “flight,” “chase”) is the intellectual masterpiece of music. Its structure is built on a theme that travels through every voice — appearing, disappearing, returning transformed.
The absolute master of the fugue is J.S. Bach. His Well-Tempered Clavier — two books of 24 preludes and fugues in every key — remains the gold standard for every generation since. Fugues were also written by Mozart, Beethoven, Max Reger, and Hindemith. It is a form that demands the maximum from both the composer and the listener.
A fugue is built on three main elements: the subject (theme), the answer (the same theme a fifth higher), and the countersubject (a melody accompanying the theme in the other voices). After the exposition, in which the theme passes through every voice, come episodes and entries in new keys. A fugue may be on two, three, four, or more subjects, and its climactic device — the stretto (a tight, overlapping entry of the voices) — is a marvel of craft.
