काचित् समं मुकुन्देन स्वर-जातीर् अमिश्रिताः
उन्निन्ये पूजिता तेन प्रीयता साधु साध्व् इति
तद् एव ध्रुवम् उन्निन्ये तस्यै मानं च बह्व् अदात्
"Shreemad-Bhagavatam", 10.33.09: "One Gopi, joining Lord Mukunda in His singing, sang pure melodious tones that rose harmoniously above His. Lord Shree Krishna was pleased and showed great appreciation for Her performance, saying "Excellent! Excellent!" Then another Gopi repeated the same melody, but in a special metrical pattern, and Lord Shree Krishna praised Her also".
Tika by OM VishnuPad VishwaNatha ChakraVarti Thakur: "The svaras (seven notes of the scale) are born from the Shrutis. These seven svaras correspond somewhat to the cries of the peacock, chataka, goat, crane, cuckoo, stork and elephant.
There are eighteen jatis (chromatic tones) which arise from these svaras. Jatis are the source of ragas.
There are two types of jatis: pure and distorted. The pure jatis are the seven harmonic tones known as sadja, rishabha, gandhara, madhyama, pancama, daivata and nisada.
When they are transformed (flattened or sharpened) they are known as distorted (vikrta).
Though they all sang, Lord Shree Krishna did not sing at the same time (amishritah) as the gopis. Another meaning of "amishritah" is that the gopis sang with pure jatis, not mixed with any intermediate tones.
This was possible because the Gopi was singing only these pure harmonic tones, due to Her Supreme Expertise. Although She was performing this difficult feat, She vibrated them excellently.
Appreciating the skilfull singing of this Gopi, Lord Shree Krishna honored Her by giving His yellow chadar.
Authorities conclude that this Gopi was Shreemati Vishakha-Devi.
Another Gopi expertly performed the alapa of one song with dhruva tala. Lord Shree Krishna honored Her with ornaments such as finger rings, jewel-studded necklaces and His own slippers.
This Gopi displayed even more excellence than Vishakha and was none other than Lalita-Sakhi.
Seeing that the Gopis were reluctant to bring the ragas and raginis they sung to even greater levels of beauty, Radha Herself then sang.
From this we can understand that among all the gopis, Radha was endowed with most the Excellent and Attractive of all qualities".
Cited from
"SARARTHA DARSHINI BY SHRILA VISHVANATHA CAKRAVARTI THAKURA",
10th canto, ENG, translated by Bhanu Swami, 2004 - http://vishnudut1926.blogspot.ru/2015/03/sarartha-darshini-by-shrila-vishvanatha.html