"And now, before we go to bed, let us sing the school song!" cried Dumbledore. Harry noticed that the other teachers' smiles had become rather fixed.
Dumbledore gave his wand a little flick, as if he was trying to get a fly off the end, and a long golden ribbon flew out of it, which rose high above the tables and twisted itself, snakelike, into words.
"Everyone pick their favorite tune," said Dumbledore, "and off we go!" And the school bellowed:

"Hogwarts, Hogwarts, Hoggy Warty Hogwarts,
Teach us something please,
Whether we be old and bald
Or young with scabby knees,
Our heads could do with filling
With some interesting stuff,
For now they're bare and full of air,
Dead flies and bits of fluff,
So teach us things worth knowing,
Bring back what we've forgot,
just do your best, we'll do the rest,
And learn until our brains all rot.


Everybody finished the song at different times. At last, only the Weasley twins were left singing along to a very slow funeral march. Dumbledore conducted their last few lines with his wand and when they had finished, he was one of those who clapped loudest.
"Ah, music," he said, wiping his eyes. "A magic beyond all we do here! And now, bedtime. Off you trot!"

Harry Potter and the Philosopher's Stone - Chapter 7 : The Sorting Hat
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