Monzo: Difference between revisions
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For example, the interval [[15/8]] can be thought of as having <math>5 \cdot 3</math> in the numerator, and <math>2 \cdot 2 \cdot 2</math> in the denominator. This can be compactly represented by the expression <math>2^{-3} \cdot 3^1 \cdot 5^1</math>, which is exactly equal to 15/8. We construct the monzo by taking the exponent from each prime, in order, and placing them within the {{monzo| … }} brackets, hence yielding {{monzo| -3 1 1 }}. | For example, the interval [[15/8]] can be thought of as having <math>5 \cdot 3</math> in the numerator, and <math>2 \cdot 2 \cdot 2</math> in the denominator. This can be compactly represented by the expression <math>2^{-3} \cdot 3^1 \cdot 5^1</math>, which is exactly equal to 15/8. We construct the monzo by taking the exponent from each prime, in order, and placing them within the {{monzo| … }} brackets, hence yielding {{monzo| -3 1 1 }}. | ||
Here are some common [[5-limit]] monzos, along with their factorizations to show how to derive them: | |||
Here are some common [[5-limit]] monzos, | |||
{| class="wikitable center-1" | {| class="wikitable center-1" | ||
|- | |- | ||
! Ratio | ! Ratio | ||
! Factors | |||
! Monzo | ! Monzo | ||
|- | |- | ||
| [[3/2]] | | [[3/2]] | ||
| <math>2^{-1} \cdot 3</math> | |||
| {{monzo| -1 1 0 }} | | {{monzo| -1 1 0 }} | ||
|- | |- | ||
| [[5/4]] | | [[5/4]] | ||
| <math>2^{-2} \cdot 5</math> | |||
| {{monzo| -2 0 1 }} | | {{monzo| -2 0 1 }} | ||
|- | |- | ||
| [[9/8]] | | [[9/8]] | ||
| <math>2^{-3} \cdot 3^2</math> | |||
| {{monzo| -3 2 0 }} | | {{monzo| -3 2 0 }} | ||
|- | |- | ||
| [[81/80]] | | [[81/80]] | ||
| <math>2^{-4} \cdot 3^4 \cdot 5^{-1}</math> | |||
| {{monzo| -4 4 -1 }} | | {{monzo| -4 4 -1 }} | ||
|} | |} | ||
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|- | |- | ||
! Ratio | ! Ratio | ||
! Factors | |||
! Monzo | ! Monzo | ||
|- | |- | ||
| [[7/4]] | | [[7/4]] | ||
| <math>2^{-2} \cdot 7</math> | |||
| {{monzo| -2 0 0 1 }} | | {{monzo| -2 0 0 1 }} | ||
|- | |- | ||
| [[7/6]] | | [[7/6]] | ||
| <math>2^{-1} \cdot 3^{-1} \cdot 7</math> | |||
| {{monzo| -1 -1 0 1 }} | | {{monzo| -1 -1 0 1 }} | ||
|- | |- | ||
| [[7/5]] | | [[7/5]] | ||
| <math>5^{-1} \cdot 7</math> | |||
| {{monzo| 0 0 -1 1 }} | | {{monzo| 0 0 -1 1 }} | ||
|} | |} | ||
:'''Practical hint:''' On the wiki, the monzo template helps you getting correct brackets ([[Template:Monzo|read more…]]). | |||
== Relationship with vals == | == Relationship with vals == | ||
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=== Subgroup monzos === | === Subgroup monzos === | ||
{{Main| | {{Main|Subgroup monzos and vals}} | ||
A subgroup monzo is like a standard monzo, except that it is in a just intonation [[subgroup]] that is not a prime limit. It is usually provided along with the subgroup it is in, such as 2.3.7 [1 -2 1⟩ for 14/9 or 2.3.13/5 [1 -1 1⟩ for 26/15. For subgroups with primes as basis elements (such as 2.3.7), a subgroup monzo can be seen as a standard monzo abbreviated to hide zeroes. To make this more clear, the abbreviated sections may be replaced with ellipses, such as 2.3.7 [1 -2 ... 1⟩ for 14/9. | A subgroup monzo is like a standard monzo, except that it is in a just intonation [[subgroup]] that is not a prime limit. It is usually provided along with the subgroup it is in, such as 2.3.7 [1 -2 1⟩ for 14/9 or 2.3.13/5 [1 -1 1⟩ for 26/15. For subgroups with primes as basis elements (such as 2.3.7), a subgroup monzo can be seen as a standard monzo abbreviated to hide zeroes. To make this more clear, the abbreviated sections may be replaced with ellipses, such as 2.3.7 [1 -2 ... 1⟩ for 14/9. | ||
=== Tempered monzos === | === Tempered monzos === | ||
{{Main| | {{Main|Tempered monzos and vals}} | ||
A tempered monzo represents a tempered interval, or an interval in a regular temperament. It functions similarly to a subgroup monzo, except each entry represents not a JI interval but a generator for that regular temperament. For example, the tmonzo for the major third in meantone (or more generally, the diatonic major third in a fifth-generated temperament) is ~2.~3 [-6 4⟩. (Note that we write the generators with tildes to indicate that they are tempered intervals). This means that to find the major third, you go up four perfect twelfths (~3/1) and down six octaves (~2/1). | A tempered monzo represents a tempered interval, or an interval in a regular temperament. It functions similarly to a subgroup monzo, except each entry represents not a JI interval but a generator for that regular temperament. For example, the tmonzo for the major third in meantone (or more generally, the diatonic major third in a fifth-generated temperament) is ~2.~3 [-6 4⟩. (Note that we write the generators with tildes to indicate that they are tempered intervals). This means that to find the major third, you go up four perfect twelfths (~3/1) and down six octaves (~2/1). | ||