So many types of guitar-like instruments have been palyed over the centuries that it may be useful to define what is meant by the term guitar. This definition would help to clarify the characteristics of instruments designated as guitars, distinguishing between them and similar stringed instrument such as lutes, ukuleles or banjos.
In partnership with Carl Sachs, he formulated a detailed list of insttrumental types. They decided that the main familiesof instruments could grouped as follows:
- Idiophones (80 entries): cymbals, triangle, gongs, castanets, bells, xylophone, glockenspiel, etc.
- Membranophones (43 entries plus 20 suffix entries): drums, where a membrane or skin is stretched a resonating cavity.
- Chordophones (79 entries): instruments producing sound by means of vibration of one or more strings stretched between two fixed points (plucked chordophones - guitar, lute, harp, etc; bowed chordophones - violin, cello, etc.).
- Aerophones (122 entries): blowing instruments using vibration of the air (trumpets, clarinets, flute, bagpipes, whistles, etc.)
Using the above table as a guide, the guitar can be clearly defined as a chordophone. Hornbostel and Sachs classified two predominant types of chordophones :
- In 'Simple Chordophone', a string tensed across a bow (used for shooting arrows), or bow-like structure, is vibrated to produce an audible twanging sound. When a gourd, box, or shell is attached to the bow, the sound is amplified. Many instruments world-wide work on this principle and this kind of chordophones is regarded as the ancestor of all plucked instruments. Ex: ganza (Lower Guinea), the hade and the thomo (South Africa), the vina (India), the chakhe (South-east Asia), the qin (China), the koto (Japan), the kani (Liberia), etc.
- In 'Composite Chordophones', string bearer and resonator are origanically united and cannot be seperated without destroying the instrument. These include instruments of great diversity in shepe and sound. Ex: Lutes, Bowl Lyres, Box Lyres (kithara, the most important string instrument of Geco-Roman antiquity and the word kithara is etymologically close to guitar), Spike lutes, spike bowls (found in Iran, India , and Indonesia), Spike box lutes or spike guitar, Necked lutes, Necked bowl lute (mandolin, theorbo, balalaika), Necked box lutes or necked guitars (violin, viol, guitar).
The guitar, like the lute is made of wood but posseses a more box-shaped resonator. The distinctive shape of the guitar's resonator, often with incurved waist and flat back, is generally characteristic of the instrument.
As with lute, guitars usually have a circular soundhole in the center of the table, while the violin family have f shaped holes. It is also customary in the lute construction, that the instrument should be as light as possible, while the guitar is heavier.
(Source: A Concise History of the Classical Guitar, Graham Wade)
