A mechanical metronome is a device used by musicians to keep a steady tempo while practicing or performing. It produces a regular ticking sound at a set beats per minute (BPM), helping musicians maintain consistent timing. The device typically features a pendulum that swings back and forth, with a weight that can be adjusted to change the tempo. These metronomes are often made of wood or plastic and can be wound up to operate without batteries. They are popular among pianists, guitarists, and other instrumentalists for developing rhythm skills and improving overall musical performance.