Hereafter

These are scenes from The Sweet Hereafter, an awarded film directed by Atom Egoyan (1997, Canada). The film is based on the novel (of the same title) by Russell Banks (1991).
The story is simple and heartbreaking. A school bus from a small American town runs into an accident, as a result of which almost all the town's children die. The accident is not in the focus as much as the aftermath, the impact it had on the town.
And indeed, Hameln, too, must have become... strange and new.

Where waters gushed and fruit-trees grew,
And flowers put forth a fairer hue,
And everything was strange and new

Krysař

This is the opening scene of Krysař, a renowned animated film directed by Jiří Barta (1986). In this version of the Pied Piper of Hamelin, it is not the rats that infest the town and it is not for the rats that the Piper comes to Hameln.
In the opening scene, Barta introduces the city of Hameln as a character in its own right. Hameln is a mythological, gothic Gormenghast, a one single jointed, twisted structure. It is a medieval town of blacksmiths and iron, without even a trace of trees, grass or birds. The underlying machines of the town set the sunrise in Hameln, and the risen sun is of dim quality that does not allow for a full palette of colours.
Townsmen - cubist puppets of dark walnut wood - are an integrated non-separable part of Hameln. Barta explained in an interview for Kinoeye that he wanted to show the townsmen as mere puppets, as wooden machines, in striking contrast to the emotional, dynamic and dramatic world of rats (also visually, since real dead rats were used to create the rat puppets).
"The puppets' world," explained Barta, "is one of horror."
Barta further dehumanized the townsmen as he made them squeak in unintelligible gibberish, while the Pied Piper, Agnes and the old fisherman remain markedly silent. The Pied Piper keeps his silence even when he is insulted by the townsmen and paid, mockingly, with a black button.
Barta's Pied Piper does not retaliate in the same way as Grimms' one. At sunrise, he stops the time in Hameln and begins to pipe.

Gothic Goethe

Goethe wrote "Der Rattenfänger" (1802) as a monologue, a first person narrative (in verse), by the Rat-catcher himself. Goethe, who considered to write the Piper into "Faust", in the role of Mephistopheles' friend and servant, made the Pied Piper seductive and boastful. Indeed, how would the Pied Piper perceive himself? As a seducer, whether of rats, children or maidens:

Sometimes the bard so full of cheer
As a child-catcher will appear,
Who even the wildest captive brings,
Whenever his golden tales he sings.
However proud each boy in heart,
However much the maidens start,
I bid the chords sweet music make,
And all must follow in my wake.

Yet, what would Goethe's seducer be without a pipe? A very, very dangerous man. For Goethe's Piper is no musician.
The posted composition is Goethe's poem made into an art song (Lied) by Hugo Wolf, a Slovenian composer. While the singing is seductive, boastful and even cheerful, the instrumental accompaniment is
frantic
gothic
insane
decadent

Where have all the young ones gone, long time ago…

"He returned on June 26, Saint John's and Saint Paul's Day, early in the morning at seven o'clock (others say it was at noon), now dressed in a hunter's costume, with a dreadful look on his face and wearing a strange red hat. He sounded his fife in the streets, but this time it wasn't rats and mice that came to him, but rather children: a great number of boys and girls from their fourth year on,"

can be read in The Children of Hameln, a folk tale as recorded by Jacob and Wilhelm Grimm (1816, Deutsche Sagen).
"In total," recorded the Grimms, "130 were lost."
There is no evidence that the legend of the Rat-catcher (or the Pied Piper) is actually based on any real event. The fact that the event is told to have happened on a specific date rather than once upon a time seems to lend the tale authenticity in the public eye. What is essentially a folk tale has been repeatedly recorded as an actual event. Being that these recordings are themselves centuries old, they lend yet another aura of authenticity to the legend.

"In the year 1284 after the birth of Christ
From Hameln were led away
One hundred thirty children, born at this place,"

is inscribed, centuries long already, on the town hall of Hameln. The town records begin with "the event" – an event that may very well have never happened. The “fact” is kept eerily alive by town regulations that prohibit any music to be heard on the Pied Piper’s (so-called “drumless”) street.
Many explanations have been offered of the actual event in 1284 that might have spawned the legend. Please refer to Wikipedia for these. As for me, I am far more fascinated by the tale itself, its many possibilities and reincarnations in art over time. These I will bring before you in the coming days.
So far, I’ve been quoting Robert Browning’s excellent rendition, The Pied Piper of Hamelin (1905).

Once more he stept into the street;
And to his lips again
Laid his long pipe of smooth straight cane;
And ere he blew three notes (such sweet
Soft notes as yet musician's cunning
Never gave the enraptured air)
There was a rustling, that seemed like a bustling
Of merry crowds justling at pitching and hustling,
Small feet were pattering, wooden shoes clattering,
Little hands clapping, and little tongues chattering,
And, like fowls in a farm-yard when barley is scattering,
Out came the children running.
All the little boys and girls,
With rosy cheeks and flaxen curls,
And sparkling eyes and teeth like pearls,
Tripping and skipping, ran merrily after
The wonderful music with shouting and laughter.

Posted above is Ingrid Bergman’s take on Browning’s verse. Bergman's reading is charming and endearing, and all the more deliciously creepy for that.