The guitar has an unequal standard tuning system - perfect fourths between each adjacent string pair except the third and second, which are tuned to a major third. Guitarists frequently use unison pitches to tune the guitar. In a system called relative tuning, the pitch of the open fifth string is matched to the fifth fret of the sixth string. This procedure is duplicated until the third string where the unison for the second string is found on the fourth fret to accommodate the major third. Although unison notes have the same pitch, they have a slightly different sound.
Musicians often use words like warm, bright, dark, fat, or thin when talking about timbre.
The Vihuela was popular in the 16th century. In the early nineteenth century Fernando Sor and Mauro Giuliani helped to popularize the guitar in European cities. In the 19th century Antonio Torres made improvements to the guitar design to increase resonance . Andr s Segovia of Spain popularized the guitar's role in classical music, becoming the most celebrated guitarist of the 20th century. Segovia Many references and representations of plucked string instruments can be found in the artistic and literary works of ancient cultures.