Holdrian comma

In music theory and musical tuning the Holdrian comma, also called Holder's comma, and sometimes the Arabian comma, is a small musical interval of approximately 22.6415 cents, equal to one step of 53 equal temperament, or ${\displaystyle {\sqrt[{53}]{2}}}$ ( play ). The name comma is misleading, since this interval is an irrational number and does not describe the compromise between intervals of any tuning system; it assumes this name because it is an approximation of the syntonic comma (21.51 cents)( play ), which was widely used as a measurement of tuning in William Holder's time.

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