Natyashastra
गीतानां मद्रकादीनां योज्यमेकं तु गीतकम् । वर्धमानमथापीह ताण्डवं यत्र युज्यते ॥ १३॥
The songs, such as those from Madra and others, should be combined into one musical piece, and here, the growing form of the Tandava should be used where it is appropriate.
english translation
gItAnAM madrakAdInAM yojyamekaM tu gItakam । vardhamAnamathApIha tANDavaM yatra yujyate ॥ 13॥
hk transliteration by Sanscript