Antonio de Torres Jurado was a Spanish guitarist and luthier, known as the most important Spanish guitar maker of the 19th century. He is credited with designing the first modern classical guitars. Most acoustic guitars in use today are derivatives of his designs. Torres was born in 1817 and worked as a carpenter before apprenticing as a guitar maker in the 1840s. Through the advice of guitarist and composer Julián Arcas, Torres began building guitars in earnest and soon became an inveterate investigator of guitar construction. He perfected the symmetrical design and reasoned that the soundboard was key to the guitar's volume.