Abstract: A device and method for very rapidly and accurately tuning each string of a guitar by contacting the string perpendicularly in order to change the tension in the string. The device is located at a position between the bridge of the guitar and the end of the guitar string. A tensioning member consisting of a shaft and disk is located perpendicularly to each string. The disk has a string engagement means which contacts the string. The tensioning member is connected to a stepping motor. The stepping motor causes the tensioning member to displace axially. The vertical movement of the member causes the disk to contact the string perpendicularly and change the tension in the string, causing the string to become tuned.