Period

The period of a scale is the interval at which the scale pattern repeats. Another word for the period is the interval of repetition. A scale with a period is known as a periodic scale. The period is usually the same size as the equave (interval of equivalence) or a fraction thereof.

In mos scales, the period is one of the two defining intervals, the other being the generator. For example:

• The diatonic scale (LLsLLLs) has period equal to the octave.
• The diminished scale (sLsLsLsL) has period 1\4, since 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.