Alpharabian comma: Difference between revisions

 

The '''Alpharabian comma''' is the [[11-limit]] interval '''131769/131072''' measuring about 9.2[[¢]]. It is the amount by which a stack of two [[128/121]] diatonic semitones falls short of a [[9/8]] whole tone. The term "Alpharabian" comes from Alpharabius – another name for Al-Farabi – and was chosen due to the fact that [[33/32]], also known as the the Al-Farabi Quartertone, is the primary limma of the 11-limit, a fact which lends itself to the idea of just 11-limit tuning being called "Alpharabian tuning" in the same way that just 3-limit tuning is called "Pythagorean tuning". Given that the Alpharabian comma and the Pythagorean comma are similar in that both commas represent the difference between two of their respective p-limit's primary diatonic semitones and a 9/8 whole tone, it follows that tempering out the Alpharabian comma results in a member of the '''Alpharabian family'''.