The ancestors of the modern guitar, like numerous other chordophones, can be traced back through numerous 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 would suggest that contemporary Iranian instruments such as the tanbur and setar are distant cousins of the European guitar, as they all derive ultimately from the same ancient origins, but by very different historical routes and influences.

Historians are not all in agreement as to how the instrument that would become the modern classical guitar found its way to Europe, but we do know that in the Early Middle Ages, instruments with three or four strings called ‘guitars’, were present on the Iberian Peninsula. An impressive variety of stringed instruments appear in the illustrations that accompany the Cantigas de Santa Maria (426 songs devoted to the Virgen Mary), which were written in the 13th century during the reign of Alfonso the Wise of Spain. These miniatures are a primary source of information as to which instruments were used to perform these songs, and include paintings of two instruments that share some characteristics with the modern-day guitar: the Latin guitar and the Moorish guitar.

The construction and tuning of these two medieval instruments were different to that of the modern guitar, however. The Latin guitar, or Guitarra Latina, possibly descended from the cithara, an instrument introduced by the Romans during their colonization of Hispania (218 BC-5^th century). This guitar had a narrow neck, curved sides, four sets of double strings and a single hole. The Moorish guitar, or Guitarra Morisca, was brought to Spain by the Moors during their occupation of Al-Andalus (711-1492), as they called the territory that is now Spain, or was an adaptation of the Latin Guitar. In fact, it looked a little bit like something between a Latin guitar and a lute and had a wider fingerboard than the Latin guitar, an oval soundbox and many sound holes on its soundboard. 

It seems possible that a process similar to a ‘natural selection’ of chordophones took place on the Iberian Peninsula during the 14^th and 15^th centuries: some instruments died out, whilst others adapted and changed as they became more popular. By the 16^th century, two instruments had evolved that were clearly precursors of the instrument we know as the guitar today. These were the vihuela de mano and the four-course guitar.

The vihuela had six or sometimes even seven double courses of strings and was built like a large guitar. It was the favoured instrument of the ‘cultured’: royal musicians played Renaissance music on the vihuela to the noblemen and noblewomen at court. The vihuela was also very popular in Italy, possibly because Naples and Sicily were under the Spanish rule of the House of Aragon. 

The four-course guitar, in contrast, was played by the common people in the town and countryside, for strumming the chords of popular songs. It was also a much smaller instrument than the vihuela. It had ten frets and the strings of this instrument (three double courses and one single, at the top) were tuned C-F-A-D, which corresponded to the centre four courses of the vihuela. It was popular all over Europe.

During the next three centuries several important changes occurred in the evolution of the guitar. In the Baroque period, a fifth double string was added to the four-course guitar. Called the five-course vihuela or five-course guitar, it supplanted both the vihuela and four-course guitar to become the most popular instrument of the time. One of the reasons why it was so well received was that it was much simpler to play Baroque music than Renaissance music, and resulted in a huge increase in the number of guitar players across the European continent. In Italy and France, this Baroque instrument was known as a chitarra spagnuola.

The first treatise to the ‘Spanish guitar’ appeared in 1596 with the publication of Guitarra Española de cinco órdenes (Five-Course Spanish Guitar), written by Juan Carlos Amat. A doctor by trade, Amat was also a guitar aficionado, and his book described in nine chapters how to string, tune and strum the chords of a five-course guitar. It became an early modern-era best-seller.

By the end of the 18^th century, the Spanish guitar had acquired a sixth string and the double courses of strings had been replaced by single strings: E-A-D-G-B-E. The change from double to single strings was the result of the invention of metal bass strings which had more volume than traditional gut strings. Although there was some resistance among guitar players to this new form of string, the manufacture of instruments with double strings gradually became obsolete. 

During the 19th century the Spanish master luthier and guitarist Antonio de Torres Jurado gave the contemporary classical guitar its definitive form. Known as the ‘father’ of the modern guitar, Torres increased the size of the instrument, made the soundboard thinner and lighter, and perfected an internal bracing system in the form of a fan that improved the strength of the instrument as well as the distribution of the sound waves. He also invented the ‘Spanish heel’, whereby the neck and headblock are carved from one piece of wood, and a part of the neck remains inside the body of the guitar when the instrument is assembled. Torres is also credited with the development of the classical guitar’s first cousin, the flamenco guitar.

In the 20^th century, the contribution of Spanish virtuoso Andres Segovia to the history of the guitar cannot be over emphasized. He legitimized the Spanish guitar by separating it from its reputation of being a folkloric instrument fit only for playing in cafes and bars and introducing it to a global audience; Segovia secured the future of this magnificent instrument by proving it was worthy of the most renowned concert halls in every corner of the globe.