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Interval information
Ratio 729/704
Monzo [-6 6 0 0 -1
Size in cents 60.41206
Name(s) Alpharabian infraaugmented prime,
Alpharabian infraapotomic quartertone,
undecimal major diesis
open this interval in xen-calc

729/704, conventionally named the undecimal major diesis[1], is a medium comma measuring about 60.4 ¢. In Alpharabian tuning, it is called the Alpharabian infraaugmented prime or Alpharabian infraapotomic quartertone.

It is a type of quartertone that differs from 33/32 by 243/242, and is itself the interval left over after subtracting 33/32 from 2187/2048. While many may be accustomed to thinking of 33/32 and 729/704 as "semiaugmented primes", this analysis is only completely accurate when 243/242 is tempered out. This interval differs from the simpler 28/27 by the symbiotic comma.

See also