Guitar is a plucked instrument that produces sound through the vibration of its strings.

There is a metal wire around the neck of the guitar, and the left hand holds the back of the neck with the thumb to fix the position of the hand. Press the strings with the index finger, middle finger, ring finger, and little finger. By pressing specific strings between different pianos with the fingers of the left hand, the strings are closely connected to the metal wires, which can change the length of the string vibration. At the same time, using the thumb, index finger, middle finger, and ring finger of the right hand to pluck the strings that need to produce sound can produce different heights of sound. Of course, tools such as paddles can also be used to remove the strings on the right hand.

When a string vibrates, it undergoes a change in tension along the direction of the string. When the tension becomes tight, a downward pressure is generated on the panel through the bridge, and an upward tension is generated by pulling the panel through the code. Therefore, the panel before the bridge will move downwards, and the panel after the code will move upwards. When the tension is restored, the panel state returns, causing continuous up and down torsional vibration.

It is not difficult to see from the vibration transmission principle above that vibrating the strings in a direction perpendicular to the panel can increase the pressure and tension obtained by the panel, and make the panel vibrate fully. This is the key to producing good sound for the guitar.