Historians estimate that the first guitar-like instrument was created 4,000 years ago. Some suggest that the guitar is the evolution of the lute, or a wind instrument. The earliest type of string instrument created was called a bowl harp. Things like tortoise shells were used as resonators.
The egyptians created many string instruments, and overtime they developed the sound box, where the resonator is hollow and is able to amplify the instrument more effectively. Slowly, the instrument became popular around the world. Europeans and Spaniards used the lute, the Indians used the citar, and the Persians used the Chartar.
Similar to the Speed of Sound in Metal lab, a guitar string (rather than a metal shaft) is plucked which causes it to oscillate transversely at a frequency which produces sound. The highest string on the guitar, when plucked without holding any frets down, oscillates at 329.63 Hz, producing an E. The lowest string on the guitar, when plucked without any frets down oscillates at 82.41 Hz, producing a lower E.
When you pluck a guitar http://www.acoustic string, a standing transverse wave is produced which is s.salford.ac.uk/fescho audible a little over a second, in ols/waves/guitarvide most circumstances. The frequency at which that o.htm wave oscillates is the frequency of the fundamental that will be produced. Of course, harmonics are also produced, but we’ll get into that later.
F=V/λ The frequency of the sound produced is equal to the speed of the wave in the guitar string divided by the wavelength. The speed of the wave in the guitar string is dependant on the tension of the string, T, and the linear mass density of the string, u. V = Sqrt of ( T / u) Velocity equals the square root of tension, divided by linear mass density. In our equation F=V/λ, we can see that the higher the velocity, the higher the frequency. In our equation V = Sqrt of ( T / u), we can see that as the string gets tighter , the frequency will increase. When tuning a guitar string, you tighten the string to reach a higher pitch. In our equation V = Sqrt of ( T / u), we can also see that as the density increases, the frequency will decrease. This is why the low E string is much thicker than the E string, and therefore produces a lower pitch, despite their tightness being somewhat similar.
F=V/λ As we can see in our equation for frequency, the higher the wavelength, the lower the frequency. When plucked openly (without any frets pressed down), all of the strings have the same wavelength. This wavelength is double the distance from the strings two pivot points (remember the speed of sound in metal lab.) When you press down a fret, you decrease the wavelength making the frequency increase. Pretty simple stuff! Why then, are the frets not spaced evenly? In music, each successive note (half-steps) is successively 1.0595 higher. That means, the first fret must make the string 5.95% smaller than its original size. The second fret must then make the string 12.12% smaller than its original size. Successively, the distance decreases until you have (1.0595 ^ 12 = 1.5) meaning that the twelfth fret will give you double the frequency, a whole octave higher.
The sound that the oscillation of the string produces isn’t loud enough for people to hear. The purpose of the body of the guitar is to amplify the sounds that the strings produce. The vibrations of the strings make the wood on the bridge of the guitar vibrate similarly, amplifying the sound. In the videos in the link, you will see 3D models of these vibration waves. The shape of the guitar, the specific dimensions of the sound box, the width of the wood, the thickness and type of wood and many more things contribute to making each acoustic guitar have a http://www.phys.un unique sound. The specifics of all of these things are too sw.edu.au/music/gui complicated to get into here. tar/virtual.html
Like other instruments, the guitar produces harmonics which help to produce and make the timbre of the sound unique. The amplitude of these harmonics, and what harmonics are able to exist in the guitar make it sound different than other instruments. Pinch harmonics (I’ll do my best to demonstrate ) occur when you lightly apply pressure to a location on the string and pluck the string. When you do a pinch harmonic on the 12th fret, you’re pressing down on the node of the 1st overtone (as well as the 3rd and 5th etc…) , which mutes the fundamental, but allows the 1st overtone to be produced.
Depending on how you touch the string, and where you touch http://www.bsharp.o it, sounds with different timbres will rg/physics/guitar be produced. In the link, you will see that if you pluck a string at the 12th fret, where the apex of the fundamental exists, the fundamental will be significantly louder than if you pluck a string at the far end of the fret board or bridge. This makes sense if you look at the image in the previous slide.