Imitation (music) in the context of "Josquin des Prez"

In classical music, a fugue (/fjuːɡ/, from Latin fuga, meaning 'flight' or 'escape') is a contrapuntal, polyphonic compositional technique in two or more voices, built on a subject (a musical theme) that is introduced at the beginning in imitation (repetition at different pitches), which recurs frequently throughout the course of the composition. It is not to be confused with a fuguing tune, which is a style of song popularized by and mostly limited to early American (i.e. shape note or "Sacred Harp") music and West Gallery music. A fugue usually has three main sections: an exposition, a development, and a final entry that contains the return of the subject in the fugue's tonic key. Fugues can also have episodes, which are parts of the fugue where new material often based on the subject is heard; a stretto (plural stretti), when the fugue's subject overlaps itself in different voices, or a recapitulation. A popular compositional technique in the Baroque era, the fugue was fundamental in showing mastery of harmony and tonality as it presented counterpoint.

In the Middle Ages, the term was widely used to denote any works in canonic style; however, by the Renaissance, it had come to denote specifically imitative works. Since the 17th century, the term fugue has described what is commonly regarded as the most fully developed procedure of imitative counterpoint.

In music, a canon is a contrapuntal (counterpoint-based) compositional technique that employs a melody with one or more imitations of the melody played after a given duration (e.g., quarter rest, one measure, etc.). The initial melody is called the leader (or dux), while the imitative melody, which is played in a different voice, is called the follower (or comes). The follower must imitate the leader, either as an exact replication of its rhythms and intervals or some transformation thereof. Repeating canons in which all voices are musically identical are called rounds—familiar singalong versions of "Row, Row, Row Your Boat" and "Frère Jacques" that call for each successive group of voices to begin the same song a bar or two after the previous group began are popular examples.

An accompanied canon is a canon accompanied by one or more additional independent parts that do not imitate the melody.

Toccata (from Italian toccare, literally, "to touch", with "toccata" being the action of touching) is a virtuoso piece of music typically for a keyboard or plucked string instrument featuring fast-moving, lightly fingered or otherwise virtuosic passages or sections, with or without imitative or fugal interludes, generally emphasizing the dexterity of the performer's fingers. Less frequently, the name is applied to works for multiple instruments (the opening of Claudio Monteverdi's opera L'Orfeo being a notable example).

A round (also called a perpetual canon [canon perpetuus], round about or infinite canon) is a musical composition, a limited type of canon, in which multiple voices sing exactly the same melody, but with each voice beginning at different times so that different parts of the melody coincide in the different voices, but nevertheless fit harmoniously together. It is one of the easiest forms of part singing, as only one line of melody need be learned by all singers, and is part of a popular musical tradition. They were particularly favoured in glee clubs, which combined amateur singing with regular drinking. The earliest known rounds date from 12th-century Europe. One characteristic of rounds is that, "there is no fixed ending", in the sense that they may be repeated as many times as possible, although many do have "fixed" endings, often indicated by a fermata.

"Row, Row, Row Your Boat" is a well-known children's round for four voices. Other well-known examples are "Frère Jacques", "Three Blind Mice", "Kookaburra", and, more recently, the outro of "God Only Knows" by The Beach Boys.