At the end of the 16th century, the guitars and hand violas of the Renaissance became transformed into a simpler, more versatile instrument. In 1586, Joan Carles i Amat published the first known treatise on the guitar. He describes two styles of five-string guitar playing: the Castilian and the Catalan. The six-stringed version became popular in the 18th century, for sophisticated music and for dances and accompanying songs.