Natyashastra
शारीराश्चैव वैणाश्च सप्त षड्जादयः स्वराः । [निषादर्षभगान्धारमध्यपञ्चमधैवताः ॥] ततं चैवावनद्धं च घनं सुषिरमेव च ॥ २७॥
The bodily and stringed sounds are the seven notes: Shadja, Rishabh, Gandhara, Madhyama, Panchama, Dhaivata, and Nishada. These are followed by flat, sharp, and open notes, along with dense and hollow sounds.
english translation
zArIrAzcaiva vaiNAzca sapta SaDjAdayaH svarAH । [niSAdarSabhagAndhAramadhyapaJcamadhaivatAH ॥] tataM caivAvanaddhaM ca ghanaM suSirameva ca ॥ 27॥
hk transliteration by Sanscript