metronome

A metronome produces a steady pulse at a tempo set by the user, measured in beats per minute (BPM). The mechanical metronome, patented by Johann Maelzel in 1816, uses an inverted pendulum with an adjustable weight — moving the weight up slows the tempo, moving it down speeds it up. Beethoven was one of the first composers to add metronome markings to his scores, though many of his markings are controversially fast. The metronome remains essential for practice — it develops a musician's internal sense of steady time. However, performing with metronomic precision is generally considered unmusical — subtle fluctuations in tempo are what give human performance its life and expressiveness.