“Suddenly another voice spoke, low and melodious, its very sound an enchantment. Those who listened unwarily to that voice could seldom report the words that they heard; and if they did, they wondered, for little power remained in them. Mostly they remembered only that it was a delight to hear the voice speaking, all that it said seemed wise and reasonable, and desire awoke in them by swift agreement to seem wise themselves. When others spoke they seemed harsh and uncouth by contrast; and if they gainsaid the voice, anger was kindled in the hearts of those under the spell. For some the spell lasted only while the voice spoke to them, and when it spoke to another they smiled, as men do who see through a juggler’s trick while others gape at it. For many the sound of the voice alone was enough to hold them enthralled; but for those whom it conquered the spell endured when they were far away, and ever they heard that soft voice whispering and urging them. But none were unmoved; none rejected its pleas and its commands without an effort of mind and will, so long as its master had control of it.”
JRR Tolkien, The Two Towers.