How Does an Electric Metronome Work?

Parts of a Metronome

Most metronomes consist of a small, often pyramid-shaped case, which displays a scale set behind a pendulum arm. The pendulum, instead of hanging from the top of the case, is mounted at the bottom so that the top end swings back and forth.

A mechanical metronome uses a double-weighted pendulum. One weight is inside the case at the bottom of the pendulum to counter-balance a weight mounted on the pendulum itself. This second weight is adjustable, sliding up or down the pendulum to establish the length of swing desired by the user. The farther down the pendulum the weight is set, the faster the arm moves.

The "Tick"

Simply moving the pendulum is not enough to make a metronome useful. Its essence lies in its ticking sound. Whether a metronome is driven by a mechanical wind-up mechanism or a battery, when the pendulum moves, it activates a mechanism inside the case to produce a loud click or, in the case of an electronic metronome, a beep or chime. Most metronomes can be set to produce a steady rate between 40 and 208 beats per minute. Some can produce two sounds to distinguish the downbeat from the upbeat.