metronome

A metronome is a device that marks time by producing a regular audible beat at a chosen tempo. The tempo is measured in beats per minute (BPM) and can be adjusted to suit the music or exercise. The name derives from Greek metron 'measure' and nomos 'law'.

In its modern form, the metronome was developed in the early 19th century. Dietrich Nikolaus Winkel designed an early pendulum model around 1814–1815, and Johann Nepomuk Maelzel later manufactured and marketed a refined version from 1816 onward. Maelzel's version became widely associated with the instrument in many countries.

Traditional metronomes are mechanical devices with a swinging pendulum and an adjustable sliding weight to set tempo; the mechanism may be wound or spring-driven. Electronic metronomes use a quartz oscillator to generate a steady click, beep, or light signal. Many models offer subdivisions (for example, eighth or sixteenth notes), preset tempos, tap tempo, and rhythm patterns for complex practice.

Uses and practice: metronomes are common tools for practicing scales, techniques, and pieces, for tempo training, and for coordinating ensembles. They help establish a consistent tempo but should not replace musical phrasing or rubato when appropriate. Today, metronomes range from compact mechanical devices to digital units and smartphone apps, often including additional features such as MIDI output.