Steel-string acoustic guitar
Steel-string acoustic guitar
 An Aria AW series steel-string acoustic guitar | |
| String instrument | |
|---|---|
| Classification | String instrument (plucked) |
| Hornbostel-Sachs classification | 321.322-6 (Composite chordophonesounded by a plectrum) |
| Playing range | |
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| Related instruments | |
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A steel-string acoustic guitar is a modern form of guitar descended from the classical guitar, but strung with steel strings for a brighter, louder sound. They are often referred to simply asacoustic guitars, although strictly speaking the nylon-strung classical guitar is acoustic as well. The most common type can be called a flat-top guitar to distinguish it from the more specialized archtop guitar and other variations.
The standard tuning for an acoustic guitar is E-A-D-G-B-E (low to high), although many players, particularly fingerpickers, use alternate tunings (scordatura), such as "open G" (D-G-D-G-B-D), "open D tuning" (D-A-D-F♯-A-D), or "drop D" (D-A-D-G-B-E).
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[edit]Construction
There are many different variations on the construction of, and materials used in, steel-string guitars. The various combinations of the different woods and their quality, along with design and construction elements (for example, how the top is braced), are among the factors affecting the timbre or "tone" of the guitar. Many players and builders feel a well-made guitar's tone improves over time.
[edit]Styles
Acoustic guitars are commonly constructed in several different body shapes. In general, the guitar's soundbox can be thought of as being composed of two connected chambers; the "upper bout" and "lower bout", which meet at the "waist", or the narrowest part of the body face near the soundhole. The proportion and overall size of these two parts helps determine the overall tonal balance and "native sound" of a particular body style, the larger the body, the louder the volume.
- A "00", "Double-Oh" or "Grand Concert" body style is the major body style most directly derived from the classical guitar. It has the thinnest soundbox and the smallest overall size of the major styles, making it very comfortable to play but also one of the quietest. Their smaller size makes them suitable for younger or smaller-framed players. These guitars are commonly called "parlor steels" as they are well-suited to smaller rooms. Martin's 00-xxx series, and Taylor's GC series, are common examples.
- A "Grand Auditorium" guitar, sometimes called a "000" or "Triple-Oh", is very similar in design to the Grand Concert, but slightly wider and deeper. Many GA-style guitars also have a convex back panel to increase the volume of space in the soundbox without making the soundbox deeper at the edges, which would affect comfort and playability. The end result is a very balanced tone, comparable to the 00, but having greater volume and dynamic range, with slightly more low-end response, without sacrificing the ergonomics of the classical style, making these body styles very popular. Eric Clapton's signature Martin guitar, for example, is of this style. Taylor's GA and x14 series and Martin's 000-xxx series are well-known examples of the Grand Auditorium style.
- A "Dreadnought", arguably the most common body style, incorporates a deeper soundbox, but a smaller and less-pronounced upper bout (the area of the soundbox between the waist and neck) than most other styles, giving a somewhat wedge-shaped appearance, hence its name, relating to a class of warship. The dreadnought style was designed by Martin Guitars [1] to produce a deeper sound than "classic"-style guitars, with very present bass fundamentals. The body style's combination of small profile with deep sound has made it immensely popular, and it has since become widely copied by virtually every major steel-string luthier. Martin's "D" series such as the D-28 are classic examples of the dreadnought.
- A "Jumbo" body style is bigger again than a Grand Auditorium but similarly proportioned, and is generally designed to provide a deeper tone similar to a dreadnought (the body style was designed by Gibson to compete with the dreadnought[1]) but with maximum resonant space for greater volume and sustain. This comes at the expense of being oversized, with a very deep sounding box, and thus somewhat more difficult to play. The foremost example of this style would be the Gibson J-200, but like the dreadnought, most guitar manufacturers have at least one jumbo model.
Any of these body styles can optionally incorporate a "cutaway". A cutaway guitar has a redesigned upper bout that removes a section of the soundbox on the underside of the neck, hence, "cutaway". This allows for easier access to the frets that are located on top of the soundbox past the heel of the neck. The tradeoff is reduced soundbox volume, and often a change in bracing, which can change the resonant qualities and hence the tone of the instrument.
Another variation on the standard acoustic guitar is the 12-string guitar, which sports an additional doubling string for each of the traditional six strings. This guitar was made famous by artists such as Lead Belly, Pete Seeger, and Leo Kottke.
All of the above guitars are relatively traditional in looks and construction, and are all commonly referred to as "flattop" guitars. Virtually all of these are commonly seen and heard in popular music genres including rock, blues, country, and folk. However, other styles of guitar have been introduced and enjoy moderate popularity, generally in more specific genres:
- The archtop guitar incorporates a top, either carved out of solid wood or heat-pressed using laminations, that is arched like instruments in the violin family, usually with f-holes rather than a round sound hole. These guitars are most commonly used by swing and jazz players and often incorporate electronics in the form of a pickup. However, many other kinds of acoustic guitars may incorporate these kinds of electronics as well.
- The "Selmer-Maccaferri guitar" is usually played by those who follow the style of Django Reinhardt. It is an unusual-looking instrument, distinguished by a fairly large body with squarish bouts, and either a "D"-shaped or longitudinal oval soundhole. The strings are gathered at the tail like an archtop guitar, but the top is flatter. It also has a wide fingerboard and slotted head like a nylon-string guitar. The loud volume and penetrating tone make it suitable for single-note soloing and it is frequently employed as a lead instrument in gypsy swing.
- The resonator guitar or resophonic guitar produces sound with one or more metal cones (resonators) instead of the wooden soundboard (guitar top/face). Resonator guitars were originally designed to be louder than conventional acoustic guitars which were overwhelmed by horns and percussion instruments in dance orchestras. They became prized for their distinctive sound, however, and found life with several musical styles (most notably bluegrass and also blues) well after electric amplification solved the issue of inadequate guitar sound levels.
[edit]Tonewoods
Traditionally, steel-string guitars have been made of a combination of various "tonewoods", or woods that have pleasing resonant qualities when used in instrument-making. Foremost is Sitka spruce, the most common and sought-after wood for the making of guitar tops. The same wood is generally used for the back and sides of a particular guitar; Brazilian rosewood and American mahogany are traditional choices, howevermaple has been prized for the figuring that can be seen when it is cut in a certain way (such as "flame" and "quilt" patterns). A common non-traditional wood gaining popularity is sapele, which is tonally similar to mahogany but slightly lighter in color and possessing a deep grain structure that is visually appealing.
Due to decreasing availability and rising prices of premium-quality traditional tonewoods, many manufacturers have begun experimenting with alternate species of woods or more commonly available variations on the standard species. For example, some makers have begun producing models with redcedar or mahogany tops, or with spruce variants other than Sitka. Cedar is also common in the back and sides, as isbasswood. Entry-level models, especially those made in East Asia, often use nato wood, which is again tonally similar to mahogany but is cheap to acquire. Some have also begun using non-wood materials, such as plastic or graphite. Carbon-fiber and phenolic composite materials have become desirable for building necks, and at least one high-end luthier (Composite Acoustics) produces a line of all-carbon-fiber guitars, prized for their high stability in changing climates that would cause wood instrument panels to swell and shrink.
[edit]Assembly
The steel-string acoustic guitar evolved from the nylon- or gut-string classical guitar, and since steel strings have higher tension, heavier construction is required overall. One innovation is a metal bar called a truss rod, which is incorporated into the neck to strengthen it and provide adjustable counter-tension to the stress of the strings. Typically, a steel-string acoustic guitar is built with a larger soundbox than a standard classical guitar. A critical structural and tonal component of an acoustic guitar is the bracing, a systems of struts glued to the inside of the back and top. Steel-string guitars use different bracing systems from classical guitars, typically using X-bracing instead of fan bracing. (Another simpler system, called ladder bracing, where the braces are all placed across the width of the instrument, is used on all types of flat-top guitars on the back.) Innovations in bracing design have emerged, most notably the A-brace developed by British luthier Roger Bucknall of Fylde Guitars.
Most luthiers and experienced players agree that a good solid top (as opposed to laminated or plywood) is the most important factor in the tone of the guitar. Solid backs and sides can also contribute to a pleasant sound, although laminated sides and backs are acceptable alternatives, commonly found in mid-level guitars (in the range of US$300–$1000).
A unique construction method is that of Ovation Guitar Company, which uses a rounded one-piece composite plastic bowl for the back and sides of virtually all of their guitars (the top and neck are usually still wood, though newer models have introduced Next post: