She powered down her laptop and the faint noises of the disk drive died away. She even closed the window, to shut out the faint night noises. It was music, dammit, she couldn't be making this up. She listened for some minutes, trying in vain to identify the piece, or even to peg the composer. Late nineteenth or early twentieth century, if she was any judge: Sibelius? Elgar?--- no, more guts than Elgar. Shostakovich maybe? It seemed to be a suite of dances for---gosh, you couldn't really identify the solo instrument. It could be anything from violin to theremin, and whatever accompaniment it had couldn't make it through the walls.
Or was it coming through the walls at all? She opened the window. The wind whistling in the trees, the river chuckling over a patch of rapids, the hoot of an owl. Definitely not coming from outside, echoing across the river valley from some solitary transistor on the far bank---which was damn near stright up and down and thick with timber. She closed the window again.
No, it was definitely inside, not outside. She opened the door and listened in the hallway. Nothing there. She closed the door again. Oh, yes, definitely in here: a piece like a Baroque gigue, a foot-tapping beat, a piece to dance to, or a march for three-legged Martians.