Шеңбер: Үздіксіз қайталамалы ән өнері

Song sung in parts indefinitely

A round (also called a perpetual canon [canon perpetuus] or infinite canon) is a musical composition, a limited type of canon, in which multiple voices sing exactly the same melody at the unison (and may continue repeating it indefinitely), 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 parts, 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. A catch is a round in which a phrase that is not apparent in a single line of lyrics emerges when the lyrics are split between the different voices. Rounds that fall into the category of "perpetual canon" feature a melody whose end leads back to the beginning, allowing easy and immediate repetition. Often, "the final cadence is the same as the first measure".

Classical composers who turned their hand to the round format include Thomas Arne, John Blow, William Byrd, Henry Purcell, Louis Hardin, Joseph Haydn, Wolfgang Amadeus Mozart, Ludwig van Beethoven, and Benjamin Britten (for example, "Old Joe Has Gone Fishing", sung by the villagers in the pub to keep the peace, at the end of act 1 of Peter Grimes) Examples by J. S. Bach include the regular canons, Var. 3 and Var. 24 of the Goldberg Variations, and the perpetual canons, Canon 7 of The Musical Offering and Canon a 2 Perpetuus (BWV 1075). Several rounds are included amongst Arnold Schoenberg's thirty plus canons, which "within their natural limitations are brilliant pieces, containing too much of the composer's characteristically unexpected blend of seriousness, humour, vigour and tenderness to remain unperformed". Contemporary classical composers, such as Abbie Betinis, have also explored round writing in the 21st century.