What was the song the choir sung in Goblet of Fire, right before the intros for the other schools started? And who is the artist? It's very distinct and totally has different words to it, compared to 'Double Trouble'.
If the question is referring to the YouTube video in the first comment, that song is the Hogwarts School Song as described in the first book Harry Potter and the Philosopher's Stone -
Chapter 7: The Sorting Hat:
'And now, before we go to bed, let us sing the school song!' cried Dumbledore...'everyone pick their favorite tune,' said Dumbledore, 'and off we go!' And the school bellowed:
Hogwarts, Hogwarts, Hoggy Warty
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
They all finished at different times because they all sang to their own song tune. That was in the facts on the 2 disk.