256/255: Difference between revisions

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{{Infobox Interval
{{Infobox Interval
| Name = septendecimal kleisma, <br>charsma, <br>diasemisma, <br>255th subharmonic
| Name = septendecimal kleisma, <br>char(i)sma, <br>diasemisma, <br>255th subharmonic
| Color name = 17ug1, sugu 1sn, <br>Sugu comma
| Color name = 17ug1, sugu 1sn, <br>Sugu comma
| Comma = yes
| Comma = yes
}}
}}


'''256/255''', the '''septendecimal kleisma''', '''charsma''', '''diasemisma''' or '''255th subharmonic''' is a [[small comma|small]] [[17-limit]] [[superparticular]] comma about 6.8 [[cent]]s in size. It is the difference between [[16/15]] (classical diatonic semitone) and [[17/16]] (large septendecimal semitone, also called as ''minor diatonic semitone''), and forms the amount by which a stack consisting of [[15/8]] and 17/16 falls short of an [[octave]]. It differs from [[352/351]] (the minthma) by [[936/935]] – an [[unnoticeable comma]] measuring about 1.85 cents.
'''256/255''', the '''septendecimal kleisma''', '''char(i)sma''', '''diasemisma''' or '''255th subharmonic''' is a [[small comma|small]] [[17-limit]] [[superparticular]] comma about 6.8 [[cent]]s in size. It is the difference between [[16/15]] (classical diatonic semitone) and [[17/16]] (large septendecimal semitone, also called as ''minor diatonic semitone''), and forms the amount by which a stack consisting of [[15/8]] and 17/16 falls short of an [[octave]]. It differs from [[352/351]] (the minthma) by [[936/935]] – an [[unnoticeable comma]] measuring about 1.85 cents.


By tempering it out is defined the '''charsmic temperament''' (full 17-limit rank-6) or '''charic temperament''' (2.3.5.17 subgroup rank-3), which enables the [[diasemismic chords|charsmic chords]].
By tempering it out is defined the '''charsmic temperament''' (full 17-limit rank-6) or '''charic temperament''' (2.3.5.17 subgroup rank-3), which enables the [[diasemismic chords|charsmic chords]].
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The name ''diasemisma'' was named by [[User:Xenllium|Xenllium]] in May 2023. It is a contraction of ''diatonic semitone'' into a single word; it is unrelated to the [[diasem]] scale structure. However, ''septendecimal kleisma'' and ''255th subharmonic'' were attested much earlier.
The name ''diasemisma'' was named by [[User:Xenllium|Xenllium]] in May 2023. It is a contraction of ''diatonic semitone'' into a single word; it is unrelated to the [[diasem]] scale structure. However, ''septendecimal kleisma'' and ''255th subharmonic'' were attested much earlier.


[[User:Godtone|Godtone]] named this comma ''charisma'' in December 2023, referring to the comma being a superparticular ratio with the numerator is 2<sup>8</sup> (the number of combinations in a byte, often referred to as a char in programming). Later, this name was revised to ''charsma'' (no-''i'' spelling) by Xenllium in January 2024 for disambiguation (formerly ''charisma'' and ''charismic'' were used for [[Magic family #Horcrux|horcrux extensions]]).
Starshine (from the [[XA Discord]] server) suggested (half-jokingly) that a chance had been missed to name it the ''charisma'' in December 2023, a name which [[User:Godtone|Godtone]] took favor to and championed. A revision to ''charsma'' (no-''i'' spelling) was proposed by Xenllium in January 2024 for disambiguation (formerly ''charisma'' and ''charismic'' were used for [[Magic family #Horcrux|horcrux extensions]]); the only issue taken with this is its inconsistency with the -ic -ismic -isma rule and that the temperaments were already suggested to be renamed in the proposal by Godtone for this and other reasons. The "char" in the name "charisma" refers to the char data type in C-derived programming languages, where the char represents a byte of at least or exactly 8 bits. Thereby, the maximum unsigned value for an 8-bit char is 255 and the number of values an 8-bit char can take is 256, hence [[256/255]].


== See also ==
== See also ==

Revision as of 17:51, 9 January 2024

Interval information
Ratio 256/255
Factorization 28 × 3-1 × 5-1 × 17-1
Monzo [8 -1 -1 0 0 0 -1
Size in cents 6.775876¢
Names septendecimal kleisma,
char(i)sma,
diasemisma,
255th subharmonic
Color name 17ug1, sugu 1sn,
Sugu comma
FJS name [math]\displaystyle{ \text{P1}_{5,17} }[/math]
Special properties square superparticular,
reduced,
reduced subharmonic
Tenney height (log2 nd) 15.9944
Weil height (log2 max(n, d)) 16
Wilson height (sopfr(nd)) 41
Comma size small
S-expression S16
Open this interval in xen-calc

256/255, the septendecimal kleisma, char(i)sma, diasemisma or 255th subharmonic is a small 17-limit superparticular comma about 6.8 cents in size. It is the difference between 16/15 (classical diatonic semitone) and 17/16 (large septendecimal semitone, also called as minor diatonic semitone), and forms the amount by which a stack consisting of 15/8 and 17/16 falls short of an octave. It differs from 352/351 (the minthma) by 936/935 – an unnoticeable comma measuring about 1.85 cents.

By tempering it out is defined the charsmic temperament (full 17-limit rank-6) or charic temperament (2.3.5.17 subgroup rank-3), which enables the charsmic chords.

Etymology

The name diasemisma was named by Xenllium in May 2023. It is a contraction of diatonic semitone into a single word; it is unrelated to the diasem scale structure. However, septendecimal kleisma and 255th subharmonic were attested much earlier.

Starshine (from the XA Discord server) suggested (half-jokingly) that a chance had been missed to name it the charisma in December 2023, a name which Godtone took favor to and championed. A revision to charsma (no-i spelling) was proposed by Xenllium in January 2024 for disambiguation (formerly charisma and charismic were used for horcrux extensions); the only issue taken with this is its inconsistency with the -ic -ismic -isma rule and that the temperaments were already suggested to be renamed in the proposal by Godtone for this and other reasons. The "char" in the name "charisma" refers to the char data type in C-derived programming languages, where the char represents a byte of at least or exactly 8 bits. Thereby, the maximum unsigned value for an 8-bit char is 255 and the number of values an 8-bit char can take is 256, hence 256/255.

See also