metronome [2]

Spring-activated pendular instrument whose beats can be synchronized with the tempo of a piece of music while practicing.

sliding weight

Adjustable weight that is moved along the pendulum bar to regulate the frequency of the beats.

tempo scale

Scale calibrated to a number of beats per minute (40 to 208) and used to match the tempo of a given piece of music (adagio, allegro, vivace and so forth).

pendulum bar

Metal rod that oscillates from one side of an axis to the other to produce a sound signal.

case

escapement mechanism

Mechanism that controls the spring release, thereby regulating the oscillations of the pendulum.

fixed weight

Counterbalance of the pendulum; its back and forth movement triggers a clacking sound.

pivot

Stem on which the wheels of the spring mechanism turn.

key

Part that rewinds the mechanism, consisting of a series of wheels.