CHĀNDOGYA UPANISHAD · 1.7.9

कं ते कामम् आगायानीति ।
एष ह्य् एव कामागानस्येष्टे य एवं विद्वान् साम गायति साम गायति ॥

kaṃ te kāmam āgāyānīti ।
eṣa hy eva kāmāgānasyeṣṭe ya evaṃ vidvān sāma gāyati sāma gāyati ॥

'What wish shall I obtain for you by my songs?' For he who knowing this sings a Sâman is able to obtain wishes through his song, yea, through his song.

F. Max Müller · The Upanishads, Sacred Books of the East 1 (1879)