# Period

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The **period** of a MOS scale is the interval at which the MOS pattern repeats. Another word for the period is the **interval of repetition**. It is usually the same size as the equave (interval of equivalence) or a fraction thereof. Along with the generator, it is one of the two defining intervals of a MOS. For example:

- The diatonic scale (LLsLLLs) has period equal to the octave.
- The diminished scale (sLsLsLsL) has period 1\4, because the MOS pattern sL repeats at every 300 cents.

The same definition applies for a rank-2 temperament, when the temperament is seen as generating a MOS. Every interval of a rank-2 temperament is a sum of some number of the period and some number of the generator of the temperament.