The Electric Guitar (Gibson SG)

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Origin of the Electric Guitar and its materials

The electric guitar has been one of the most influential, pivotal instruments of modern popular music, and the primary factor behind entire musical ideas and genres. Today, the electric guitar is one of the most widely played and produced instruments. The electric guitar’s popularity and influence today can be traced back to 1925, when ex-American National String Instrument Company engineer George Beauchamp began attempting to produce an electric guitar pickup out of an alnico horseshoe magnet wound with copper wire to create an electrical current by magnetising the vibrations of steel guitar strings when they were strummed. This current would then pass into a tube radio amplifier to produce an audible,sonic note from the electrical signal. Beauchamp, with the help of designer Paul Barth, turned this idea into reality over the next 5 years and by 1931 the first electric guitar, a Hawaiian lap steel guitar nicknamed ‘The Frypan’, was produced by Beauchamp and Barth. The two men commissioned Adolph Rickenbacker, of the Rickenbacker Tool and Die Company to mass produce ‘The Frypan’. This technology was adapted by Gibson Company luthier Lloyd Loar in 1933 to produce the first electric Spanish guitar, the hollow-body Gibson ES-150, which went onto the market in 1935 and featured alnico pickups, stainless steel strings and a mahogany neck. This was first electric Spanish guitar to be played widely by notable artists such as Charlie Christian and paved the way for electric guitars and the technological advancement that led to iconic solid-body models, such as the Rickenbacker 620, Gibson SG, Gibson Les Paul and the Fender Telecaster and Stratocaster, which are immortal instruments highly valued by guitar players worldwide today.


Alnico was first produced in 1921 by metallurgist Dr T. Mishima in Tokyo, Japan. Alnico is used in the guitar pickup due to its magnetic properties, which allows it to produce a strong electrical signal to be amplified. Mahogany timber is the specific timber used for the body of the Gibson SG. Mahogany a type of tropical, reddish-brown hardwood, and has been used since prehistory by indigenous Central and South American people. The strings on the Gibson SG are manufactured from Stainless Steel, an alloy consisting of Iron, Carbon and Chromium, which differs from regular steel in its ability to resist corrosion and retain strength. Stainless Steel was first discovered by French Metallurgist Pierre Berthier in 1821. Stainless Steel as is used today was first patented and mass produced in 1912 by German Company ThyssenKrupp Nirosta. These three materials form the basis of the sonorous capabilities of the Gibson SG Electric Guitar, each with specific properties contributing to the iconic sound and status of this guitar in Modern Musical History.

Evolution of the Electric Guitar

The Evolution of the electric guitar can be traced by the different guitars which have been released since the Rickenbacker 'Frypan' in 1930, each with a new innovation that has contributed to the evolution of the electric guitar. The following are the most popular electric guitars in history and the ones which have exercised the greatest influence upon popular music and the evolution of the electric guitar.

Guitar Model Year Details Image
Gibson ES-150 1935 The Gibson ES-150 was the first Spanish-style electric guitar to be successful on the global market. It was the first mass-produced Spanish guitar to employ Alnico pickups, with copper coil and stainless steel strings. The Gibson ES-150 is a hollow-body electric guitar, thus it retained some detail of an acoustic guitar. The Gibson ES-150 was played and made famous by notable jazz musicians including Charlie Christian and Wes Montgomery
Fender Telecaster 1948 The Fender telecaster signaled a monumental step in electric guitar history; the presence of Fender as a major manufacturer. The Fender Telecaster was the first solid-body electric guitar, a technological precedent which has been followed by all electric guitars since. The Telecaster was also the first to use maple for the body, a specialty tonewood which is still used today. The telecaster also tensed strings from both the bridge and the neck, which allowed the strings to be bended by a whole tone. Notable players of the Fender Telecaster include Keith Richards, Muddy Waters and Jeff Beck.
Gibson Les Paul 1952 The Gibson Les Paul is the most influential guitar in history, forming the basis for all guitar technology since. The Les Paul was named after the man who developed it, legendary Jazz guitarist Les Paul. The Les Paul was the first solid body electric to be released by Gibson. The Les Paul was revolutionary for three reasons. It was the first to employ multiple pickups, one for the three bass strings, and one for the three treble strings. It was the first guitar to feature humbucking pickups, which contained two coils of copper wire around the magnet, which cancelled out the electrical 'hum' that often interfered with the tone of previous electric guitars. Finally, the Les Paul was the first guitar to have a mahogany body, increasing the tonal properties of the guitar to unprecedented levels. Notable players of the Les Paul include Slash, Jimmy Page and Mick Taylor.
Fender Stratocaster 1954 The Fender stratocaster was the second Fender release. The Fender Stratocaster was innovative in its employment of three pickups, the first to do so, and specific switches on the guitar body to turn pickups on or off, thus allowing another layer of tonal control for the guitarist. The Fender stratocaster was also the first guitar with a specialist shape to allow for maximum fret access to the higher notes. This also allowed the guitar to have a lighter weight. The Fender stratocaster has been played by David Gilmour, Jimi Hendrix and Mark Knopfler, all of whom have brought their own tone and style to the identity of the Fender Stratocaster
Gibson SG 1961 The Gibson SG was the first guitar specially designed to play rock music, without any regard for jazz or country sounds. The SG deviated from previous guitars in its revolutionary shape, with cutaways at the base of the neck creating an appearance of 'horns' on the guitar. These cutaways allow for maximum access to the top frets for guitarists. The SG also has wood shaved from the sides at the back of the guitar, creating an incredibly thin, lightweight guitar, meaning that the SG was incredibly easy to manoeuvre on stage. The final innovation of the Gibson SG is the use of flat frets on the neck, which allows for quicker movement between the frets for the fingers of a guitarist, maximising the guitar's Rock appeal. The SG was made famous by guitarists including Tony Iommi, Eric Clapton, Pete Townshend and Angus Young
Ibanez Universe 1984 The Ibanez Universe was the first guitar to directly make alterations to the materials at the very heart and soul of a guitar's sound; the pickups. The Ibanez Universe introduced DiMarzio pickups, featuring ceramic magnets and silver wire as opposed to Alnico magnets and Copper wire. This prolongs the sustain phase of the signal produced by the pickup, which suits a higher output level. The Ibanez Universe was the first guitar made specially for heavy saturation and distortion of the sound, and it was accordingly adopted by guitarists including Steve Vai, Joe Satriani and Paul Stanley, who epitomised this heavy, distorted sound.

Manufacturing Processes


The Alnico magnet used in the P90 Humbucker Pickup on a Gibson SG is an anisotropic magnet, meaning that the particles in the magnet are oriented towards a magnetic field during manufacture and are thus oriented with their poles in a specific direction that can’t be altered. Anisotropic Alnico magnets are manufactured through a process of sintering. Alnico Sintering involves a mixture of powdered Iron, Aluminium, Nickel, Cobalt, Titanium and Niobium undergoing atomic diffusion at high heat. The powder mixture is placed in a sand die of the desired final shape of the magnet and heated to 1280°C, cooler than the melting point of the entire mixture, in a vacuum atmosphere of hydrogen gas, which exerts extensive pressure upon the mixture in the die. Under the pressure and heat of the hydrogen atmosphere, the atoms in the individual powder particles diffuse across the boundaries of each particle, thus fusing the powder particles together into one solid piece of Alnico metal in the shape of the die in which the powders were cast. The Alnico manufacturing process is completed with the magnetic orientation of the alloy. This is achieved through cooling the alloy, in the sand die, in the presence of a strong magnetic field, which aligns the particles in the alloy to be magnetised in the direction of the magnetic field, creating an anisotropic Alnico magnet once the alloy has completely cooled. If the desired magnetism has not been achieved through the first cooling of the alloy, it may be heated and cooled again in the presence of the magnetic field to increase magnetism to the desired level.

Chemical Equation for the Sintering of an Alnico (8) Anisotropic Magnet

Fe32+Co36+Ni13+Al7+Cu4+Ti7+Ni=Alnico (8)

Stainless Steel

The strings on a Gibson SG are made of Stainless Steel, which differs from regular steel due to the presence of a minimum of 10.5% chromium in the alloy. The presence of chromium in the alloy gives stainless steel its key property of corrosion resistance. The ferritic stainless steel used for Guitar strings consists of 0.1% carbon, 17% chromium and 82.9% iron. The manufacture of stainless steel begins with the extraction of iron ore from the Earth in mines. This iron ore generally exists as Iron Oxide (Fe2O3) with assorted silicates, manganese and phosphorus. To produce the carbon in steel, Carbon is burned to produce Carbon Dioxide. The Carbon dioxide then undergoes an endothermic reaction with pure carbon (C) to produce Carbon Monoxide (CO). The Iron Oxide then reacts with the Carbon Monoxide to produce Pig Iron (Approximately 92% Iron, 4% Carbon, 2% silicates, 1.5% manganese and the balance sulphur and phosphorus). Once the pig iron has been attained it is melted down to produce molten pig iron. The Pig Iron is then placed into a furnace and is melted down into a molten state. Stainless Steel is then made from the molten Pig Iron in the furnace through the Klockner Oxygen Blown Maxhutte Process, which involves oxygen being blown into the furnace from 6 different holes, which oxidises much of the carbon into Carbon Dioxide and oxidises all elements other than Iron present in the molten pig iron. These oxidisedelements form a slag which rises to the top of the furnace and is collected, whilst the carbon dioxide gas simply escapes into the atmosphere, leaving Steel. To make stainless steel the necessary amount of molten chromium (17% of the total alloy) is added to the furnace to produce Ferritic Stainless Steel, consisting of 17% chromium, 0.1% carbon and 82.9% iron. The molten stainless steel is poured into casts and cooled to produce solid steel.

Chemical Equations for the Manufacture of Steel

Carbon + Oxygen=Carbon Dioxide
Carbon Dioxide + Carbon=Carbon Monoxide
Fe2O3+3CO=2Fe (Pig Iron) +3CO2
Iron Ore + Carbon Monoxide=Pig Iron + Carbon Dioxide


Mahogany timber is the material used to make the body and neck of the Gibson SG. Mahogany is a naturally occurring substance, thus its production is a simple process. The Mahogany Tree is cut down by loggers and the bark stripped to expose the timber itself. The timber is then sawn to shape, depending on the use the timber is intended for. The timber is then treated with a range of herbicides and pesticides to protect the timber from damage at the hands of pests and fungal or plant growth. Moisture is then removed from the timber through evaporative humidity treatment in a wood kiln, where the timber is heated to evaporate any existing moisture from the timber to completely dry it out and protect it from moisture spoilage. Finally, the timber is again treated with a vast range of herbicides and pesticides before it is sent off to the Gibson Factory to be sanded, cut to the shape of a guitar neck or body, painted and coated with protective nitrocellulose varnish.

Environmental Impact of Electric Guitars

The three stages in the life of an electric guitar; manufacture, playing and disposal, all bear an environmental impact, the overwhelming majority of which are negative impacts. Deforestation is a key impact of large-scale electric guitar manufacture, as the main component of guitar bodies and necks is timber, usually that of endangered hardwoods including mahogany, which over time could lead to the extinction of certain species of timber. Another considerable effect of deforestation for guitar timbers is the contribution to an increase in greenhouse gases, as due to deforestation, fewer trees exist to offset greenhouse gas emissions. The paints and nitrocellulose finish on the timber of the guitar also have a negative environmental impact, as when they are sprayed onto guitar harmful fumes from these two substances are released into the air, polluting it. The factory manufacturing process of the guitar itself bears a negative impact, as electronic machinery is used for much of the production. These electronic machines are powered by the burning of coal to produce electricity, which emits copious amounts of greenhouse gases and other toxic chemicals into the atmosphere, contributing to climate change and air pollution. This environmental impact is also experienced through the use of the guitar, as amplifiers require electricity for operation, which involves the burning of coal. The mining processes for the metals used on electric guitars require large amounts of fossil fuels and electricity, further increasing the carbon footprint of electric guitar manufacture and the emission of toxic pollutants into the atmosphere. The processes of manufacturing and refining the metals once they have been extracted also bears a significant environmental impact, as massive volumes of water, fossil fuels and electricity are used to produce alnico and stainless steel. There is also considerable burning of substances involved in producing alnico and stainless steel, which emits carbon dioxide into the atmosphere, another factor contributing to the negative carbon footprint of electric guitar production. Extracting minerals from the Earth also bears the environmental impact of spoiling existing resources and ecosystems, which is another form of environmental impact as contaminants from the mining process can run into pure water supplies or soil, rendering large swathes of previously pristine, untouched land and resources spoiled and tainted. Large amounts of plastic also exist on and in an electric guitar. Plastics are produced with the burning and use of incredulous amounts of fossil fuels, which only serve to worsen the impact of the electric guitar’s production in contributing to greenhouse gases and pillaging vital resources.

The disposal of an electric guitar, although rare, also bears an environmental impact, as the guitar more often than not goes into landfill and remains in the Earth for thousands of years and certain harmful substances from the guitar, including nitrocellulose can leech into soils and contaminate them. However, the electric guitar can have a small amount of positive environmental impact as much of the guitar can be recycled. All metal substances in the guitar can be melted down and used to manufacture other products, particularly copper, stainless steel, zamak and alnico. The timber can also be recycled, although not as easily as metallic substances can.

Chemical Composition


Alnico is an alloy, meaning it is a metallic substance consisting of a mixture of metal elements. Alnico’s name is derived from its three key elements; Aluminium (Al), Nickel (Ni) and Cobalt (Co).As Alnico is an alloy it has no exact chemical formula or equation. The chemical composition of Alnico (8), the form of Alnico used in the Gibson SG P90 Guitar pickup, is
31.5% Iron
36% Cobalt
13.5% Nickel
7.2% Aluminium
3.5% Copper
7.5% Titanium
0.8% Niobium.

Stainless Steel

Stainless Steel is also an alloy, although Carbon is a metalloid and not a metal element. The Chemical Composition of Ferritic Stainless Steel, the form of stainless steel used for the strings on a Gibson SG, is
82.9% Iron
17% Chromium
0.1% Carbon.


The major component in the rigid cell walls in plants, such as mahogany, is cellulose. Cellulose is a linear polysaccharide carbohydrate polymer with many glucose monosaccharide units. 50% of mahogany wood consists of cellulose. Cellulose is an organic compound with the formula C6H5O10 Cellulose is made up of anywhere from hundreds to tens of thousands of glucose monosaccharide units, meaning that cellulose is formed from chains of glucose molecules in rings. Glucose has the chemical formula C6H12O6. One glucose molecule ring is a monosaccharide (single sugar) unit. In the case of cellulose, when many monosaccharide units form a polymer by creating a chain of rings, a polysaccharide (multiple sugar) compound is created.


Macroscopic Properties

Material Macroscopic Property Definition Use in Electric Guitar
Alnico Permanent Magnetism Permanent magnetism is a property of a substance that allows it to exert or respond to an applied magnetic field that causes the material to be either attracted or repelled to the other object applying the magnetic field. Permanent magnetism means that the substance is permanently exerting a magnetic field, due to the existence of iron in the substance The permanent magnetism of the Alnico pickup is what allows the pickup to produce an electrical signal to send to the amplifier, from which the audible note is produced. The Alnico pickup’s permanent magnetism allows the vibrations of the strings to be magnetised and create electrical current, thus this property of Alnico is the primary key to the optimal function of the electric guitar
Alnico Conductivity of Electricity Conductivity of electricity is the measure of a substance’s ability to conduct an electric current and enable its flow through the substance The high electrical conductivity of Alnico allows the pickup to easily pass the electric current created by the magnetism of string vibrations into the copper wire coil which goes into the amplifier and allows for the production of a note.
Alnico Hardness Hardness is the measure of a substance’s ability to resist denting and scratching to its surface The hardness of Alnico means that the pickup can endure contact against its surface from the copper wire and steel strings of the guitar without damage, denting or scratching and successfully produce a tone
Stainless Steel Ductility Ductility is the measure of a substance’s ability to be deformed under tensile stress, without fracture or damage, and drawn into thin wire shapes The ductility of stainless steel means that it can easily be drawn into the shape suitable for guitar strings and can endure the associated tensile strength because of its ductility.
Stainless Steel Resistance to Corrosion If a substance is resistant to corrosion it means that it is highly unlikely to experience oxidisation or corrosion and the associated deformity, leading to increased durability and strength. The strings of the guitar are exposed to the air, sweat and other body oils, all of which contribute to the corrosion and wear of the string. However, due to the corrosion resistance of stainless steel, from which the strings are made, these substances have no effect upon the strings and allow the string to last for a long time and produce a high quality sound, without corrosion.
Stainless Steel Elasticity Elasticity is the measure of a substance’s ability to return to its original shape after the deformative stress placed upon it is removed The elasticity of stainless steel strings allows a guitarist to bend and press the strings to produce a note without damage or breaking of the strings, which return to their original shape and configuration when the pressure or bending is halted by the guitarist
Mahogany Sonorous Resonance Sonorous resonance is the measure of a substance’s ability to conduct soundwaves into the air and produce a clear, rich, full sound which resonates intensely for a prolonged period of time into the surrounding area Without the sonorous resonance of the mahogany body, the guitar would not be able to produce as good a quality sound as is produced, as this property of mahogany timber is the key to the guitar projecting the best possible clear, resonant sound, which is at the very core of the guitar and the basis of its entire purpose as a top-quality musical instrument
Mahogany Durability Durability is the measure of a substance’s ability to last over a prolonged period of time and endure without serious wear or defective change in the substance The durability of mahogany ensures that the guitar’s body and neck will last for a long period of time and maintain optimal performance even if played heavily over many decades, ensuring that guitarists get the very best from their guitar
Mahogany Density Density is the mass per unit of volume in a substance, calculated as mass/volume. Low-density means that the substance has a small amount of mass in a specific volume and it thus relatively lightweight Compared to other durable, sonorous timbers suitable for use in guitars, mahogany is low-density. This makes for a lighter guitar, which makes the guitar more manoeuvrable on stage, making playing the guitar playing experience easier for the guitarist

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