Scientific pitch notation creates a linear pitch space in which an octave spans 12 semitones, where each semitone is the distance between adjacent keys of the piano keyboard. Distance in this space corresponds to musical pitch distance in an equal-tempered scale; 2 semitones being a whole step, 1 semitone being a half step. An equal-tempered semitone can also be subdivided further into 100 cents. Each cent is semitone or octave. This measure of pitch allows the expression of "microtones" not found on standard piano keyboards. The notation is sometimes used in the context of meantone temperament, and does not always assume equal temperament
Octave mandolin distinction is not crisp, and there are cases of each term being used in each country. Jimmy Moon, a Scottish luthier calls his version of the instrument by both names and Paul Shippey, an English luthier, uses the term octave mandolin. Confusion will likely continue as the terms continue to be used interchangeably. Octave mandolin construction is similar to the mandolin: the body may be constructed with a bowl-shaped back according to designs of the 18th-century Vinaccia school, or with a flat (arched) back according to the designs of Gibson Guitar Corporation popularized in the United States in the early