Quarter tone

A quarter tone  play , is a pitch halfway between the usual notes of a chromatic scale or an interval about half as wide (aurally, or logarithmically) as a semitone, which is half a whole tone.

Many composers are known for having written music including quarter tones or the quarter-tone scale (24 equal temperament), first proposed by 19th-century music theorist Mikha'il Mishaqah, and in 1823 by the German theorist Heinrich Richter, including: Pierre Boulez, Julián Carrillo, Mildred Couper, George Enescu, Alberto Ginastera, Gérard Grisey, Alois Hába, Ljubica Marić, Charles Ives, Tristan Murail, Krzysztof Penderecki, Giacinto Scelsi, Ammar El Sherei, Karlheinz Stockhausen, Tui St. George Tucker, Ivan Alexandrovich Wyschnegradsky, and Iannis Xenakis (see List of quarter tone pieces).

Types of quarter tones

The term quarter tone can refer to a number of different intervals, all very close in size. For example, some 17th- and 18th-century theorists used the term to describe the distance between a sharp and enharmonically distinct flat in mean-tone temperaments (e.g., D♯–E♭). In the quarter tone scale, also called 24 tone equal temperament (24-TET), the quarter tone is 50 cents, or a frequency ratio of 2^1/24 or approximately 1.0293, and divides the octave into 24 equal steps (equal temperament). In this scale the quarter tone is the smallest step. A semitone is thus made of two steps, and three steps make a three-quarter tone  play  or neutral second, half of a minor third.

Tone scale

In Scientology, the tone scale or emotional tone scale is a characterization of human behavior. It is based on the idea that some people appear to be more lively and alive than other people; this increased liveliness is orderly. Author L. Ron Hubbard spelled the idea out saying, "just draw a horizontal line on the page. Put the people who are less alive on the bottom and the people who are more alive on the top."

In his 1951 book Science of Survival, Hubbard expanded the idea into many increments. The idea states that a "tone" has many manifestations including appearance, chronic emotion, the way the person handles other people, how well the person can pass on a communication given to them, and other characteristics.

Scale

Details of the scale

Hubbard devised the "Tone Scale" in 1951 as a tool for auditors in Scientology. Scientologists believe it intends to classify people in a range or scale according to how spiritually alive and how dead a person is, both personally and in their relationships to others. It prescribes auditing procedures to use with a person depending where they are on the scale.

Chromatic scale

The chromatic scale is a musical scale with twelve pitches, each a semitone above or below another. On a modern piano or other equal-tempered instrument, all the semitones have the same size (100 cents). In other words, the notes of an equal-tempered chromatic scale are equally spaced. An equal-tempered chromatic scale is a nondiatonic scale having no tonic because of the symmetry of its equally spaced notes.

The most common conception of the chromatic scale before the 13th century was the Pythagorean chromatic scale. Due to a different tuning technique, the twelve semitones in this scale have two slightly different sizes. Thus, the scale is not perfectly symmetric. Many other tuning systems, developed in the ensuing centuries, share a similar asymmetry. Equally spaced pitches are provided only by equal temperament tuning systems, which are widely used in contemporary music.

The term chromatic derives from the Greek word chroma, meaning color. Chromatic notes are traditionally understood as harmonically inessential embellishments, shadings, or inflections of diatonic notes.