A metronome is a device that produces an audible click or other sound at a uniform interval that can be set by the user, typically in beats per minute (BPM). Metronomes may also include synchronized visual motion, such as a swinging pendulum or a blinking light. Musicians—and others including dancers, athletes, and health professionals—often practise with a metronome to improve their timing, especially the ability to maintain a steady tempo with a regular beat or pulse. Composers and conductors often use numerical metronome markings to communicate their preferred tempos to musicians preparing for a performance.

In musical terminology, tempo, also known as beats per minute, is the speed or pace of a given composition. In classical music, tempo is typically indicated with an instruction at the start of a piece and is usually measured in beats per minute (BPM). In modern classical compositions, a "metronome mark" in beats per minute may supplement or replace the normal tempo marking, while in modern genres like electronic dance music, tempo will typically simply be stated in BPM.