Augmented seventh Adding a diesis to this makes up an octave. Hence, this interval's complement, the diminished second, is often referred to as a diesis. Augmented seventh In classical music from Western culture, an augmented seventh is an interval produced by widening a major seventh by a chromatic semitone. For instance, the interval from C to B is a major seventh, eleven semitones wide, and both the intervals from C to B, and from C to B are augmented sevenths, spanning twelve semitones. Being augmented, it is classified as a dissonant interval. However, it is enharmonically equivalent to the perfect octave. Since
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