Tuner and Metronom
The tuner is an electronic device for tuning a musical instrument. It recognizes the tone of the instrument through structure-borne noise, via a built-in microphone or through a cable with a connected pickup, and shows on a scale whether the tone is too high, too low or correct. There are tuners that only recognize certain tones, for example only 6 strings of the guitar. While chromatic tuners recognize all 12 semitones over several octaves. The currently most common variant of tuners are the "clip-on" tuners. These are small devices which are clamped on the head of the guitar, for example. The tuner recognizes the tone directly from the structure-borne sound. The big advantage: the tuner precisely sets the tone; environmental noise is not included. The standard models are based on a built-in loudspeaker. These larger models sometimes offer more setting options or different special moods, such as 'Flat-Tuning'. Tuners are also available as pedals. These can be switched directly between guitar amp and guitar.
The metronome is a device that uses acoustic impulses to set a constant tempo at regular time intervals. Metronomes are available mechanically or electronically. Many instruments such as pianos or keyboards already have a metronome integrated. The mechanical metronome drives a pendulum with the help of a spring. The desired speed is set using a weight on the pendulum. To the left and right of the pendulum is the scale with the beats per minute. The further you push the weight up on the pendulum, the slower the metronome counts in the beat. Each click falls to the value of a quarter note. The mechanical metronome works like a mechanical clockwork. To start it up, the spring must be wound with the help of a wrench. In order for it to work precisely, it has to stand on an exactly flat surface, as any inclination affects the swing of the pendulum.
Electronic metronomes generate the clock signal through a quartz. For this reason, they are also known as quartz metronomes. You have to think of the quartz as a chip, the so-called quartz oscillator. It consists of electronic circuits and an oscillating crystal in a standardized housing. The setting of the counting times is carried out depending on the make using appropriate switches or toggle switches. The selected frequency appears on a display. Many digital metronomes have an interface to which headphones can be connected. A quartz metronome "ticks" very precisely and is therefore particularly suitable as a clock generator.
The tuning fork is a metal fork; the prongs produce a clear, overtone-poor tone when struck. This is used to tune in musical instruments.