A copper engraving plate. Drag to engrave lines — each stroke is a notch the burin would have cut. Click to place a notehead and hear its pitch.
The plate ages. Fresh engravings glow copper. After thirty seconds in the air they begin to verdigris — the green patina that forms on every plate left out long enough. The marks do not fade. They oxidize.
Drag · engrave · click · ring · wait · green