This is a charming video, but it also illustrates some deeper ideas:
• Composition. It shows how a piece of music can be rendered on an unusual instrument and remain recognizable.
• Instrument. It shows how a musical instrument can be fashioned out of descending wooden steps and a falling ball.
• Agency. It shows that a music “performance” need not have a human performer.
• Context. It shows a world of tempered melody set against a forest soundscape.