Diesis

In classical music from Western culture, a diesis (/ˈdaɪəsɪs/ DY-ə-sis; "difference"; Greek: δίεσις "leak" or "escape") is either an accidental (see sharp), or a very small musical interval, usually defined as the difference between an octave (in the ratio 2:1) and three justly tuned major thirds (tuned in the ratio 5:4), equal to 128:125 or about 41.06 cents. In 12-tone equal temperament (on a piano for example) three major thirds in a row equal an octave, but three justly-tuned major thirds fall quite a bit narrow of an octave, and the diesis describes the amount by which they are short. For instance, an octave (2:1) spans from C to C', and three justly tuned major thirds (5:4) span from C to B♯ (namely, from C, to E, to G♯, to B♯). The difference between C-C' (2:1) and C-B♯ (125:64) is the diesis (128:125). Notice that this coincides with the interval between B♯ and C', also called a diminished second.

The diesis is a comma. The above-mentioned 128:125 comma is also known as the lesser diesis, as opposed to a wider comma (648:625) known as greater diesis. As shown in the picture, in the quarter-comma meantone tuning system (a tuning system in which, by definition, major thirds are justly tuned), the diminished second coincides with the diesis.

Diesis (disambiguation)

Diesis is a small modification of music pitch.

Diesis also may refer to :

Diesis (horse)

Diesis (23 April 1980–18 November 2006) was a British Thoroughbred racehorse and sire. An outstanding two-year-old in 1982, he failed to live up to expectations at three, but went on to become an extremely successful breeding stallion, based in the United States.

Background

Diesis was a chestnut horse with a white star and three white socks bred in England by his owner 9th Baron Howard de Walden. He was sired by Sharpen Up out of the noted broodmare Doubly Sure, making him a full brother to the champion miler Kris, and a half-brother to several other good winners including Rudimentary (Sandown Mile). The colt was named after the printer's symbol "‡" also known as a "double dagger". He was trained by Henry Cecil at his Warren Place stable in Newmarket, Suffolk.

Racing career

As a juvenile, Diesis won three races from four starts. After running fifth in a maiden race on his debut he won the Rhys-Jenkins and Standing Stakes by seven lengths. He was then moved up in class and won the Group One Middle Park Stakes over six furlongs at Newmarket Racecourse in October. Later that month he returned to Newmarket for the Dewhurst Stakes over seven furlongs, in which he was matched against Gorytus an unbeaten colt from the Dick Hern stable with an exceptional reputation. Gorytus ran very poorly (he was widely believed to have been drugged) and Diesis won his second Group One race very easily. He was the highest rated European two-year-old in the 1982 International Classification, a collaboration between the official handicappers of Britain, France and Ireland. Diesis was also rated the best two-year-old of the season by the independent Timeform organisation.