A term that can refer to a texture or compositional style, as well as to a form. As a texture or style, it is highly contrapuntal, featuring multiple independent voices that are closely interwoven. As a form — developed most fully in the Baroque era — its characteristic feature is the exposition, or opening section.
The exposition begins with a melodic subject, usually with an identifiable profile, and sometimes paired with a countersubject. This is followed by sequential entries of the subject at the tonic and dominant (the latter called the answer).
A layered structure is created by these staggered entries, each restating the theme at a different pitch while earlier voices continue with independent material.

Example: Fugue Subject (Violin)

Example: Countersubject (Violin) combined with Answer at the Dominant (Flute)