Octave species various available intervals could be combined in any order, even restricting species to just the diatonic genus would result in twelve ways of dividing the octave (and his 17th-century editor, Marcus Meibom, pointed out that the actual number is 21), but "only seven species or forms are melodic and symphonic" . Those octave species that cannot be mapped onto the system are therefore rejected . In chant theory beginning in the 9th century, the "New Exposition" of the composite treatise called "Alia musica" developed an eightfold modal system from the seven diatonic octave species of ancient Greek theory, transmitted to
Sicilian octave Renaissance and has seldom been used in English except as an illustration of the form. Before the 15th century, however, it was used often by poets in southern Italy, and was an important influence for Petrarch in his sonnets. Boccaccio, who popularized and may have invented the unrelated ottava rima, used the Sicilian octave a total of once, in his early romance Filocolo. The epitaph of Giulia Topazia is a Sicilian octave: Sicilian octave The Sicilian octave (Italian: "ottava siciliana" or "ottava napoletana", lit. "Neapolitan octave") is a verse form consisting of eight lines of eleven syllables each, called a