The body of the instrument is a major determinant of the overall sound variety for acoustic guitars. The guitar top, or soundboard, is a finely crafted and engineered element often made of tonewood like spruce, red cedar or mahogany. This thin (often 2 or 3 mm thick) piece of wood, strengthened by different types of internal bracing, is considered to be the most prominent factor in determining the sound quality of a guitar. The majority of the sound is caused by vibration of the guitar top as the energy of the vibrating strings is transferred to it. It is thought that the details of the way in which the guitar top vibrates (characterised by many different modes of vibration at different frequencies) is a key influence on the timbre of the radiated sound. Different patterns of wood bracing have been used through the years by luthiers (Torres, Hauser, Ramirez, Fleta, and C.F. Martin being among the most influential designers of their times); to not only strengthen the top against collapsing under the tremendous stress exerted by the tensioned strings, but also to affect the resonance characteristics of the top. The back and sides are made out of a variety of tonewoods such as mahogany, Indian rosewood and highly regarded Brazilian rosewood (Dalbergia nigra). Each one is chosen for their aesthetic effect and structural strength, and can also play a significant role in determining the instrument's timbre. These are also strengthened with internal bracing, and decorated with inlays and purfling.
The body of an acoustic guitar has a sound hole and acts as a resonating chamber. The sound hole is normally a round hole in the top of the guitar (under the strings), though some may have different placement, shapes or multiple holes. Air inside the body vibrates as the guitar top is vibrated by the strings, and the response of the air cavity at different frequencies is characterised, like the rest of the guitar body, by a number of resonance modes at which it responds more strongly. Some sound is radiated by the movement of the air in and out of the sound hole, although the guitar top is the main radiator of sound.
Instruments with larger areas for the guitar top may have greater sound-radiating abilities, making higher volume of sound possible (although tone quality will also be affected by guitar top size and design). The popularity of the Dreadnought body size amongst acoustic performers may relate to the greater sound volume produced.
However, whilst the '00' pattern is a post-modern evolution in the wake of affordable wire-drawing and truss-turning technologies, musicians wishing to explore the nature of performance in the taverna or salon environments which overlapped early recording technologies may wish to consider the role of the 3/4-size as well as the Ordinary, or '0', guitar, particularly where a duo or ensemble is called for and space is at a premium.
Body (electric guitar)
Most electric guitar bodies are made of wood with a plastic pick guard. Boards wide enough to use as a solid body are very expensive, so the wood is rarely one solid piece. Most bodies are made of two pieces of wood with a seam running down the centre line of the body. The most common woods used for electric guitar body construction include maple, basswood, ash, poplar, alder, and mahogany. Many bodies will consist of good sounding but inexpensive woods, like ash, with a "top", or thin layer of another, more attractive wood (such as maple with a natural "flame" pattern) glued to the top of the basic wood. Guitars constructed like this are often called "flame tops". The body is usually carved or routed to accept the other elements, such as the bridge, pickup, neck, and other electronic components. Most electrics have a polyester or nitrocellulose lacquer finish.
Most electric guitar bodies are made of wood with a plastic pick guard. Boards wide enough to use as a solid body are very expensive, so the wood is rarely one solid piece. Most bodies are made of two pieces of wood with a seam running down the centre line of the body. The most common woods used for electric guitar body construction include maple, basswood, ash, poplar, alder, and mahogany. Many bodies will consist of good sounding but inexpensive woods, like ash, with a "top", or thin layer of another, more attractive wood (such as maple with a natural "flame" pattern) glued to the top of the basic wood. Guitars constructed like this are often called "flame tops". The body is usually carved or routed to accept the other elements, such as the bridge, pickup, neck, and other electronic components. Most electrics have a polyester or nitrocellulose lacquer finish.