Johann Nepomuk Maelzel

Johann Nepomuk Maelzel (or Mälzel; August 15, 1772 – July 21, 1838) was a German inventor, engineer, and showman, best known for manufacturing a metronome and several music-playing automatons, and displaying a fraudulent chess machine.

In 1804, he invented the panharmonicon, an automaton able to play the musical instruments of a military band, powered by bellows and directed by revolving cylinders storing the notes.

In 1805 Maelzel purchased Wolfgang von Kempelen's half-forgotten automaton chess player, The Turk, took it to Paris, and sold it to Eugene Beauharnais at a large profit.

Returning to Vienna, he gave his attention to the construction of an automaton trumpeter, which, with lifelike movements and sudden changes of attire, performed French and Austrian field signals and military airs.

Beethoven wrote glowingly of Maelzel's metronome and declared he would stop using traditional tempo indications like allegro.