A metronome is a device that produces regular repeated sounds at a steady tempo, indicated by beats per minute (or BPM). It has many uses for musicians and is an essential piece of music equipment for students and professionals, too. Most metronomes produce a click sound that is easy to hear for musicians while they practice. Some advanced metronomes will produce a variety of sounds (like sleigh bells) and have extra features like subdividing the beat. There are even some talking metronomes that speak the beat, so you can hear each beat of the measure you are playing.
Some students search for a “guitar metronome” or a “piano metronome.” All metronomes perform the same function and can be used by any instrument, whether it is a guitar, piano, drums, clarinet, kazoo, or anything else. See the section on how to buy a metronome for more information.
Metronomes provide several functions. They produce a steady beat so that musicians can develop a strong sense of tempo. They also let us know if we are slowing down or speeding up while practicing. Also, composers sometimes will indicate that they want their music to be performed at a specific tempo, and the metronome is used to determine that tempo. The metronome also can help us with a wide variety of practice techniques.
The earliest metronomes provided a steady pulse through the use of a pendulum. In the 16th century the great scientist Galileo conceived this pendulum idea, but he never created the actual time-keeping device. Several other musicians and scientists in the 17th and 18th centuries experimented with the idea of producing an instrument that would create a steady tempo, but it wasn’t until 1815 that Johann Nepomuk Maelzel patented the “metronome.” It was a pendulum-like instrument that had a long metal bar that swung back and forth. The tempo was changed by moving a metal weight up and down the bar. Metronomes that use this technique are still available, and you can buy a metronome that is just like the one that Maelzel created.
The history of this invention is not completely clear, and apparently Maelzel simply made some adjustments to a similar instrument created by a man named Dietrich Winkel. The changes that Maelzel made were significant, though -- he added numbers to the metal bar, indicating the beats per minute of the selected tempo. This is very valuable information for the practicing musician. Winkel sued Maelzel and won the case. However, Maelzel had already started production and had sold so many of the instruments that his name was associated with the invention of the metronome.
In the 20th century electronic metronomes were developed. They are more steady and reliable than the Maelzel metronomes, and they are capable of producing much louder clicks than the old-fashioned acoustic models. Some digital metronomes are also capable of producing a variety of different sounds and beat patterns. See the section on buying a metronome.