A/N: The challenge was to write a story in which Remus has an encounter with a Muggle artifact.
Disclaimer: Harry Potter, Remus Lupin, Arthur Weasley, and all their associates are characters belonging to J.K. Rowling. I claim no rights to them, their surroundings, or their situations. Much to my sorrow.
Polka!
---
"What is it?" Remus circled the bizarre object cautiously, completely unable to make heads or tails of it.
"It's a musical instrument," Arthur said triumphantly.
Remus crouched down next to the thing. "Are you sure?"
"Well of course I'm sure. Look, see here, it has a little keyboard--something like a harpsichord, don't you know, only miniaturized. And, er, perpendicular."
"I can see that. But a harpsichord is a stringed instrument. This thing is built more like a bellows." Remus frowned. "Doesn't quite scan, somehow."
"Well, Muggles play some jolly pleasant tunes on it, I assure you. Would you like to hear?" Brimming with enthusiasm, Arthur picked up the sinister contraption and proceeded to struggle with it for several minutes, nearly winding the heavy strap around his neck before he got everything situated properly (or so Remus presumed.)
"Arthur, really, I'm not sure this is a good idea..." Privately, Remus thought the thing looked like the invention of a particularly foul Dark Wizard. "We only just got the children settled down. Severus nodded off in the library a little while ago, too, and you know how Mrs. Black can be..."
"Nonsense, m'boy! I'll make it the quietest of lullabies. You know what they say, 'music hath charms to soothe the savage breast!' Just ask Professor Flitwick...now, er, why won't it...aha, there we are."
With that, Arthur located and disengaged the latch that held the bellows closed. The strange contraption expanded, filling with air...and, as Arthur brought his hands together, produced the most horrific cacaphony of discordant notes Remus had ever heard in his life.
He clapped his hands over his sensitive ears as the portrait of Mrs. Black began to screech, a door slammed open somewhere in the vicinity of the library, and a thunderous stampede punctuated by the excited cries of the children rolled down the stairs toward them.
Arthur met his accusing glare with a shrug and a weak, sheepish smile, then hastily ran to hide the old accordion behind a bookshelf.