An acoustic guitar is a string instrument which is one of the most recognized and played instruments in the world. But have you dug deep on how it is what it is?
An acoustic guitar has four parts:
- The Body
- The Neck
- The String
- The Air ( Have patience, You'll know why)
The body is made up of woods and each type of wood gives it a different sound. The most common woods used are:
- Spruce
- Cedar
- Mahogany
- Maple
- Rosewood
Mostly solid woods are preferred to the laminated ones.The body of the guitar transfers the vibrations of the bridge to the air that surrounds it. The top plate contributes to most of the pressure disturbances, because the player dampens the back plate and the sides are relatively stiff. As the top needs to vibrate the most, the top plate of the body is made of light and flexible woods. There are wooden supports inside an acoustic guitar which are called to be braces. They support the guitar body's frame. Also the type of braces varies from guitar to guitar and each types of braces have a uniqueness of its own.
This image gives you the idea of vibrations through out the body of the guitar. The body is connected to a neck.
The Neck is made up of solid wood and consists of divisions called frets. There are generally 19-21 frets in acoustic guitars. These frets are of steel and are raised slightly from the neck surface. When a finger is pressed between the frets the fret towards the body of the guitar touches the string and the vibration of the string is limited to that length causing the change in pitch. The neck's topmost part is the head. The head consists of tuning post around which the strings are tightened. The tuners help to tune the strings to the required pitch. The head also consists of a nut which acts like the 1st fret and is made up of bone or plastics. It is made replacable as the string is placed onto it and it bears all the pressure of the string tension in the head.
The strings in the guitar are made of nylon or steel/copper. The guitar strings vary in thickness. There are 6 strings and there sizes vary as the requirement of the player.
extra light: .010 .014 .023 .030 .039 .047
custom light: .011 .015 .023 .032 .042 .052
light: .012 .016 .025 .032 .042 .054
medium: .013 .017 .026 .035 .045 .056
heavy: .014 .018 .027 .039 .049 .059
These strings are wound and can stretch quite a bit. They are tightened to the tuner to the saddle of the guitar body.
How it works?
When you pluck a string, they vibrate as per their length thickness,density etc.This gives the guitar a wide range of attainable frequencies. The larger the linear density is, the slower the string vibrates. The same goes for the length; the longer the string is the slower it vibrates. This causes a low frequency.
where T= string tension, ρ=linear density, L = string length
So, we need to know that every string as different linear density, different tension( as every string is tightened to give a particular frequency) and different length (as per the placement of the hands in the form of chords).
SO.......
What we learned is that as per the formula above, a frequency is produced, this small sound then transmits to the body which rings with higher amplitude so as to be highly audible. The air transmits the sound and the body acts like a closed pipe. Using various combinations of string lengths i.e chords we get different sound and harmony which then connects to our soul and we perceive it as MUSIC. Now, Appreciate it as the piece of art and science :)
