Lyrics by Simon and Garfunkel.
Text from book 7 chapter 34.

Sparrow

Suddenly, he remembers the Snitch that Dumbledore willed to him – he pulls it out of the moleskin bag and reads its motto, I open at the close. It all makes sense now; he presses it to his lips, and it breaks open. In his hand is the broken ring Horcrux, with the Resurrection Stone set in it.
And he knows what it’s there for – he turns it three times in his hand and is greeted by the phantoms of those who love him but who he has lost.
Smiling lovingly at him, he sees James, Lily, Sirius, and Lupin, looking young and happy. For the first time, Harry is reunited with the parents who died to protect him – their love is written all over their faces.
Harry asks only one question – does it hurt? Sirius and Lupin comfort him, saying that it’ll be quick and easy.

Who will love a little Sparrow?
Who’s traveled far and cries for rest?
“Not I,” said the Oak Tree
“I won’t share my branches with no sparrow’s nest
And my blanket of leaves won’t warm her cold breast.“

Harry, overcome, tells them that he didn’t want any of them to die – not for him. Lupin reassures him, and says that he hopes Teddy, his now-orphaned son, will know that his parents died to make a better world.
Harry knows that they won’t tell him to go – he has to decide to do that himself.
He asks if they’ll stay with him, and they assure him that they will. They’re invisible to anyone else, and stay close to Harry, giving him comfort as he walks past the dementors, into the depths of the forest.

Who will love a little Sparrow
And who will speak a kindly word?
“Not I,” said the Swan
“The entire idea is utterly absurd
I’d be laughed at and scorned if the other Swans heard.”

Harry encounters Yaxley and Dolohov, two Death Eaters, trolling the forest. They comment that the hour’s almost up, and Harry hasn’t showed Voldemort will not be pleased.
In the middle of a clearing, Harry finds what he’s been looking for: Voldemort, surrounded by his silent followers.
Voldemort speaks. He’s surprised that Harry didn’t show up – but then Harry reveals himself, emerging from under the Cloak.
He drops the Resurrection Stone, and his protectors vanish.

And who will take pity in his heart
And who will feed a starving sparrow?
“Not I,” said the Golden Wheat
“I would if I could, but I cannot, I know
I need all my grain to prosper and grow.“

Harry and Voldemort finally face off; it feels like they’re alone there.
Harry’s distracted momentarily by Hagrid, who’s bound up to a tree nearby and is yelling at Harry not to surrender himself. A Death Eater silences Hagrid.
Bellatrix looks on, clearly full of bloodlust.
Harry doesn’t even try to draw his wand, knowing that it would be futile to try and kill Nagini right now. Voldemort contemptuously addresses Harry, and their eyes meet. Voldemort points his wand at Harry, and with a flash of green light – nothingness.

Who will love a little Sparrow?
Will no one write her eulogy?
“I will,” said the Earth
“For all I’ve created returns unto me
From dust were ye made and dust ye shall be.”