Canto

The canto () is a principal form of division in medieval and modern long poetry.
Etymology and equivalent terms.
The word "canto" is derived from the Italian word for "song" or "singing", which comes from the Latin "cantus", "song", from the infinitive verb "canere", "to sing".
In Old Saxon poetry, Old English poetry, and Middle English poetry, the term "fitt" was sometimes used to denote a section of a long narrative poem, and that term is sometimes used in modern scholarship of this material instead of "canto".
Form and use.
The use of the canto was described in the 1911 edition of the "Encyclopædia Britannica" as "a convenient division when poetry was more usually sung by the minstrel to his own accompaniment than read". There is no specific format, construction or style for a canto and it is not limited to any one type of poetry.
The typical length of a canto varies greatly from one poem to another. The average canto in the "Divine Comedy" is 142 lines long, while the average canto in "Os Lusíadas" is 882 lines long.
Examples.
Some famous poems that employ the canto division are Dante's "Divine Comedy" (with 100 cantos), Camões' "Os Lusíadas" (10 cantos), Torquato Tasso's "Gerusalemme liberata" (20 cantos), Byron's "Don Juan" (17 cantos, the last of which is unfinished) and Ezra Pound's "The Cantos" (116 cantos).