18th century, six double-strung courses had become common.

Up to this point, most stringed instruments were strung with gut strings. At around 1800, quality metal-wire strings became widely available. These new strings were more durable, remained in tune longer and, most importantly, produced a louder sound than the traditional gut strings. As use of metal strings became more widely adopted, their greater volume output impelled luthiers to experiment more with single-strung courses on their instruments and, in a relatively short time,