Kleisma (interval region)

Revision as of 11:26, 14 March 2025 by FloraC (talk | contribs) (+sagittal definition)

A kleisma is an interval of about 8.1 cents, roughly the size of the interval 15625/15552, which is called the kleisma in just intonation. In sagittal notation, it is defined specifically as between half of the 200-comma ([317 -200⟩) and half of the Pythagorean comma ([-19 12⟩).

← Unnoticeable comma Kleisma Small comma →
Name Kleisma
Lower bound 6¢
Upper bound 9¢
Example JI intervals
Intervals 15625/15552 (8.1¢)
243/242 (7.1¢)
225/224 (7.7¢)
1029/1024 (8.4¢)
16875/16807 (7¢)
65536/65219 (8.4¢)
Related regions
Superregion(s) Small comma
Comma
Comma and diesis

The kleisma is significant as it is a limit of intonational fidelity when playing on some physical instruments. That is, on free-pitch instruments, there is a level of precision to which one can be expected to play a note or interval "correctly": that level of precision is the kleisma. Another significance is that a lot of commas are about 3–4 kleismas in size.

Kleismas belong to the larger interval region of commas, which are part of the "comma and diesis" category.

See also



View • Talk • EditInterval classification
Interval regions
Unison and octave Unison • Comma and diesis • Octave
Seconds Minor second • Neutral second • Major second
Thirds Minor third • Neutral third • Major third
Fourths and fifths Perfect fourth • Superfourth • Tritone • Subfifth • Perfect fifth
Sixths Minor sixth • Neutral sixth • Major sixth
Sevenths Minor seventh • Neutral seventh • Major seventh
Interseptimal intervals Interseptimal 2nd-3rd • Interseptimal 3rd-4th • Interseptimal 5th-6th • Interseptimal 6th-7th
Interval qualities
Diatonic qualities Diminished • Minor • Perfect • Major • Augmented
Tuning ranges Neutral (interval quality) • Submajor and supraminor • Pental major and minor • Novamajor and novaminor • Neogothic major and minor • Supermajor and subminor • Ultramajor and inframinor