A Canon, with one "n" in the middle, is a composition with two or more voices or parts in which a melody is first stated in one voice and then imitated in another.
The type of canon in which the voices return to the beginning of a melody each time the reach the end is called a perpetual canon, or more commonly, a round. "Row, Row, Row Your Boat" is a round as is "Three Blind Mice." Did you know that "The Three Blind Mice" was originally published in the year 1609? In England from 1500's to the 1700's, a type of round called the catch, always sung by three of more male voices, became tremendously popular. Catches are cleverly constructed so that the words of the individual parts overlap to create humorous juxtapositions. Well, actually obscene juxtapositions is more like it. Catches like "Three Blind Mice" were published in large collections and some Englishmen even formed private societies for the specific purpose of singing catches.
A Minute with Miles - a production of ETV Radio, made possible by the JM Smith Corporation.