The [instrument named] Tāla is of the ‘solid’ class (ghana), and it relates to a division into Kalās (kalāpāta) and to an observation of the tempo (laya). Those who apply Tālas in a musical performance, should know Kalās to be the measure of time (tāla).
या लौकिकी कला काष्ठा निमेषश्च स्मृतो बुधैः । न सा तालकला ज्ञेया ह्यन्यैषा तालजा कला ॥ २॥
The popular Kalā, [together with] the Kāṣṭhā and Nimeṣa, which has been accepted (lit. remembered) by the wise, is not the Kalā in [observing] the Tāla. The Kalā arising from the Tāla is different.
Five Nimeṣas will make one Mātrā, and the Kalā arises from the grouping of Mātrās. And five Nimeṣas are also to be known as [the period of] interval between [two] Kalās, at the time of singing. And from these again, the tempo is made according to the time of the Kalās [into which they (Mātrās) are divided].
The tempo (laya) is of three kinds: quick (druta), medium (madhya) and slow (vilambita), and among these, the medium tempo determines the normal Kalā (pramāṇa-kalā).
कलाकालप्रमाणेन ताल इत्यभिसञ्ज्ञितः । त्रिविधा सा च विज्ञेया त्रिमार्गनियमा बुधैः ॥ ५॥
The Tāla is so called because it is defined by the measure of Kalā and Kāla (time). It is known to be of three kinds, determined by the three Mārgas, according to the wise.