"Silencio."
A cloaked man tenderly turned the doorknob and grinned in a cruel glee as the door gave him entry. Taking care not to make a sound, he crept into the hall and soon found the room he was looking for -- the study. He slipped in and found it empty but for furniture -- most notable of which was a massive ebony piano. Beside it was a desk, its cover closed and doubtless locked. He quietly moved to the desk and pointed his wand to the keyhole.
"Alohomora."
A light click announced the spell's efficiency. With a satisfied smirk, the wizard started to lift the cover when it gave a loud squeak. His blood froze as he prayed that the mistress of the house hadn't heard.
Upstairs, a black-eyed woman turned her head slightly, still, for the most part, asleep. The soft sound of her son sleeping beside her, wrapped in his mother's blanket, and his sister beside him satisfied her maternal instincts so she laid her head to rest once more.
In the study, the wizard held his breath for one minute...two minutes...five...but nothing happened. Still wary, he whispered a silencing charm on the entire room, but decided she must not be home. If she wasn't home, he could have a bit of fun, but he couldn't have the neighbors hearing him. He took off his Invisibility Cloak and tucked it in his robes. With a quick thrust, he opened the desk, paying no mind to its shrieks, and found, inside, stacks of paper, all a pale white -- Muggle paper. With disgust, he lifted a sheet for examination.
The paper was entitled "Eileen's Lullaby" and it was covered in lines with dots sitting on them in what seemed like a random order, but the wizard knew what it truly was -- it was a song. Songs, lyrics, notes, music books and many writing utensils -- all Muggle -- covered the desk. With a sneer, he picked up a stack.
"My my, he's been working on 'Eileen's Lullaby' for some time..." he mused with a sneer. Then, with a roar, he spun around and threw the song, letting showering all over the floor like the remnants of a whomping willow attack. Grinning evilly, he reached for more and sent paper and pencils and pens and books flying as he laughed maniacally. Drawer after drawer, his victim's life was thrown about like a quaffle and when all was misplaced, the wizard gave a shout of wicked triumph.
Then he turned to the piano. With a quick swish of his wand, the side legs disappeared and the beast crashed to the floor with a satisfying clang. He wrenched open the lid of the mammoth instrument and started pulling out chords; ivory and ebony keys joining the music on the floor. When the piano was mutilated enough for his tastes, the man pointed his wand at a heavy, dusty curtain.
"Imperio!" Immediately, the smell of burning fabric filled his nostrils and he was filled with a sweet victory as he supervised the damage, waiting until the fire had started licking across the ceiling to Disapparate to report his success.
Grandmother Prince would be pleased.