It was a wild windy morning, the bare trees on the hill all bending with a tremendous rushing sound in the wind coming over from Dartmoor. The road runs below the hilltop, so it is sheltered, but the trees up on the top were roaring.
I went up on the road that runs through the quarry, and could hear a strange distant music. The whole place was shut up, with nobody about at all. Eventually I realised that the music must be the wind blowing through the metal steps and rails and bars that are arranged around the vast funnels and tubes and pipes that the quarry uses to process its sands and gravels.
The sound was like something between tubular bells, distant church bells on a windy day, and someone blowing a tune on a series of partially-filled bottles. It was surprisingly beautiful.
I've heard mines singing before, when the wind races across the top of a chimney on a hillside, it can have a sort of deep voice. But never a whole organs-worth of accidental instruments all singing together.