In Book II, Part One, Chapter 15 of War and Peace Leo Tolstoy describes a young girl singing:
Natasha took the first note, her throat swelled, her chest rose, and her eyes took on a serious expression. At that moment she was oblivious of everyone and everything, and from her smiling lips flowed sounds that anyone may produce at the same intervals and hold for the same length of time, but leave you cold a thousand times, and the thousand and first, thrill you and make you weep.
That winter for the first time Natasha had begun to take her singing seriously, mainly because Denisov was so enthusaistic over her voice. She no longer sang like a child, there was no longer that droll, childish, painstaking effect that had been apparent before; she did not yet sing well, as the connoisseurs who heard her said. "It's not a trained voice," they all said, "but it's a beautiful voice, and must be trained." This was generally said, however, some time after she had finished singing. While they were listening to that untrained voice with its incorrect breathing and labored transitions, even the connoisseurs said nothing, and only delighted in it and wished to hear it again. Her voice had a virginal purity, an unconsciousness of its own power, and an uncultivated yet velvety quality that was so much a part of her lack of artistry in singing that it seemed as if nothing in that voice could be changed without spoiling it.