The ancestries of the modern guitar, like numerous other chordophones, track back through many instruments and thousands of years to ancient central Asia. Guitar like instruments appear in ancient carvings and statues recovered from the old Persian capital of Susa. This means that the contemporary Iranian instruments such as the tanbur and setar are distantly related to the European guitar, as they all derive ultimately from the same ancient origins, but by very different historical routes and influences.
During the Middle Ages, instruments called "guitars" with three and four strings were in use but their construction and tuning was different from the modern guitars. The Guitarra Latina in Spain, had curved sides and a single hole. The Guitarra Morisca, which was brought to Spain by the Moors or at least was heavily influenced by Moorish instruments, had an oval soundbox and many sound holes on its soundboard. By the 15th century, a four course double-string instrument called the vihuela de mano, that had tuning like the later modern guitar except on one string and similar construction, appeared in Spain and spread to Italy; by the 16th century, a fifth double-string had been added. During this time, composers wrote mostly in tablature notation. In the middle of the 16th century, influences from the vihuela and the renaissance guitar were combined and the baroque five string guitar appeared in Spain. The baroque guitar quickly superseded the vihuela in popularity in Spain, France and Italy and Italian players and composers became prominent. In the late 18th century the six string guitar quickly became popular at the expense of the five string guitars. During the 19th century the Spanish luthier and player Antonio de Torres gave the modern classical guitar its definitive form, with a broadened body, increased waist curve, thinned belly, improved internal bracing, single string courses replacing double courses, and a machined head replacing wooden tuning pegs. The modern classical guitar replaced older form for the accompaniment of song and dance called flamenco, and a modified version, known as the flamenco guitar, was created.
The written history of the classical guitar can be traced back to the early 16th century with the development of the vihuela in Spain. While the lute was then becoming popular in other parts of Europe, the Spaniards did not take to it well because of its association with the Moors. Instead, the lute like vihuela appeared with two more strings that gave it more range and complexity. In its most developed form, the vihuela was a guitar-like instrument with six double strings made of gut, tuned like a modern classical guitar with the exception of the third string, which was tuned half a step lower. It has a high sound and is rather large to hold. Few have survived and most of what is known today comes from diagrams and paintings.
The classical guitar (also called the Spanish guitar, the concert guitar or the nylon-string guitar) is a 6-stringed plucked string instrument from the family of instruments called chordophones. In addition to the instrument, the phrase "classical guitar" can refer to two other concepts:
The design of the modern classical guitar can be attributed to Antonio de Torres. The construction of these guitars has been considered the standard in "traditional" instruments since the mid 19th century.
The shape, construction, and material of classical guitars vary, but typically they have a modern classical guitar shape, or historic classical guitar shape (e.g., early romantic guitars from France and Italy). Strings are usually of nylon or other synthetic material, or fine wire wrapped around a nylon or other synthetic core. Historic guitars may have strings made of gut (sheep or pig intestine).
Contemporary concert guitars occasionally follow the Smallman design, which replaces fan braces with a much lighter balsa brace attached to the back of the sound board with carbon fiber. The balsa brace has a honeycomb pattern and allows the (now much thinner) sound board to support more vibrational modes. This leads to greater volume and longer sustain but compromises the subtle tonalities of the Spanish sound.
Right-handed players use the fingers of the right hand to pluck the strings, with the thumb plucking from the top of a string downwards and the other fingers plucking from the bottom of string upwards. The little finger in classical technique as it evolved in the 20th century is used only to ride along with the ring finger without striking the strings and to thus physiologically facilitate the ring finger's motion. Some modern guitarists, such as Štěpán Rak, use the little finger independently, compensating for the little finger's shortness by maintaining an extremely long fingernail. In contrast, Flamenco technique, and classical compositions evoking Flamenco, employ the little finger semi-independently in the Flamenco four-finger rasgueado, that rapid strumming of the string by the fingers in reverse order employing the back of the fingernail—a familiar characteristic of Flamenco.
Parts of typical classical guitars, numbered
3 Machine heads (or pegheads, tuning keys, tuning machines, tuners)
14 Bottom deck
16 Body sides
17 Sound hole, with rosette inlay
19 Saddle (Bridge nut)