Natyashastra
अथ मध्यमनीचैस्तु गच्छेद्यः परिवारितः । चतुष्कलमथार्धं च तथा चैककलं पुनः ॥ २२॥
But when accompanied by those of middling or inferior status, the tempo should be four Kalās, or two Kalās, or one Kalā accordingly.
english translation
atha madhyamanIcaistu gacchedyaH parivAritaH । catuSkalamathArdhaM ca tathA caikakalaM punaH ॥ 22॥
hk transliteration by Sanscript