Harmonic limit: Difference between revisions

From Xenharmonic Wiki
Jump to navigation Jump to search
Improve intro (free abelian group is better off not introduced first)
Facilitate navigation of individual pages of prime limits
Line 9: Line 9:
A positive rational number ''q'' belongs to the ''p''-limit for a given [[prime number]] ''p'' if and only if it can be factored into primes (with positive or negative integer exponents) of size less than or equal to ''p''. For any prime number ''p'', the set of all rational numbers in the ''p''-limit defines a [[Wikipedia: Free abelian group|finitely generated free abelian group]]. The [[rank]] of this group is equal to π (''p''), the number of prime numbers less than or equal to ''p''. Hence, for example, the rank of the [[7-limit]] is 4, as it is generated by 2, 3, 5 and 7.  
A positive rational number ''q'' belongs to the ''p''-limit for a given [[prime number]] ''p'' if and only if it can be factored into primes (with positive or negative integer exponents) of size less than or equal to ''p''. For any prime number ''p'', the set of all rational numbers in the ''p''-limit defines a [[Wikipedia: Free abelian group|finitely generated free abelian group]]. The [[rank]] of this group is equal to π (''p''), the number of prime numbers less than or equal to ''p''. Hence, for example, the rank of the [[7-limit]] is 4, as it is generated by 2, 3, 5 and 7.  


== Examples of ''p''-limits ==
== Individual pages of ''p''-limit JI ==
With increasing limits, the tonal space becomes more dense.
{| class="wikitable center-all"
 
|-
* [[2-limit]] contains only multiples of the [[octave]] (2/1), see [[1edo]]
| [[2-limit]] || [[3-limit]] || [[5-limit]] || [[7-limit]] || [[11-limit]] || [[13-limit]]
* [[3-limit]] contains [[3/2]], the [[just perfect fifth]]
|-
* [[5-limit]] contains [[5/4]], the perfect major third
| [[17-limit]] || [[19-limit]] || [[23-limit]] || [[29-limit]] || [[31-limit]] || [[37-limit]]
* [[7-limit]] contains [[7/4]], the harmonic seventh or septimal subminor seventh
|-
* [[11-limit]] contains [[11/8]], the undecimal tritone or "Alphorn-Fa"
| [[41-limit]] || [[43-limit]] || [[47-limit]] || [[53-limit]] || [[59-limit]] || [[61-limit]]
* [[13-limit]]
|-
* [[17-limit]]
| [[67-limit]] || [[71-limit]] || [[73-limit]] || [[79-limit]] || [[83-limit]] || [[89-limit]]
* [[19-limit]]
|}
* [[23-limit]]
* [[29-limit]]
* [[31-limit]]
* [[41-limit]]
* [[47-limit]]
* [[61-limit]]


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

Revision as of 09:19, 2 January 2023

English Wikipedia has an article on:

In just intonation, the p-limit or p-prime-limit consists of the ratios of p-smooth numbers, where a p-smooth number is an integer with prime factors no larger than p.

A positive rational number q belongs to the p-limit for a given prime number p if and only if it can be factored into primes (with positive or negative integer exponents) of size less than or equal to p. For any prime number p, the set of all rational numbers in the p-limit defines a finitely generated free abelian group. The rank of this group is equal to π (p), the number of prime numbers less than or equal to p. Hence, for example, the rank of the 7-limit is 4, as it is generated by 2, 3, 5 and 7.

Individual pages of p-limit JI

2-limit 3-limit 5-limit 7-limit 11-limit 13-limit
17-limit 19-limit 23-limit 29-limit 31-limit 37-limit
41-limit 43-limit 47-limit 53-limit 59-limit 61-limit
67-limit 71-limit 73-limit 79-limit 83-limit 89-limit

See also

External links