The five-course or double string guitar, known as baroque guitar, is usually considered an instrument from the 17th century or beginning of the 18th, and it is followed by the guitar of six single strings, which is the one we may find in the classical-romantic repertoire. Nevertheless, the historical reality is more complex than what we can imagine: grosso modo, we may say that, until well into the 19th century, several plucked string instruments coexisted: guitars with five double and single strings, of six double and single strings, and even guitars with seven or more strings are mentioned.