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
Eleventh Eleventh In music or music theory an eleventh is the note eleven scale degrees from the root of a chord and also the interval between the root and the eleventh. The interval can be also described as a compound fourth, spanning an octave plus a fourth. Since there are only seven degrees in a diatonic scale the eleventh degree is the same as the subdominant. The eleventh is considered highly dissonant with the third. A perfect eleventh is an eleventh which spans exactly 17 semitones. It can be also described as a compound perfect fourth, spanning an octave plus a