second bar shaped member in another embodiment of the present teachings the directing member may include a plate that is disposed between a bottom of the groove of the first bar shaped member and the second bar shaped member preferably a width of the groove of the first bar shaped member and an outer diameter of the second bar shaped member may be set to be substantially equal to each other and the directing member may comprise side walls of the groove of the first bar shaped member in another embodiment of the present teachings the second bar shaped member may be substantially coaxially disposed within the first bar shaped member in the alternative the second bar shaped member may be disposed in juxtaposed relationship with the first bar shaped member and may extend substantially in parallel to the first bar shaped member in another embodiment of the present teachings guitars are taught that may include the truing devices according to the aforementioned various embodiments each of the additional features and teachings disclosed above and below may be utilized separately or in conjunction with other features and teachings to provide improved neck truing devices for stringed instruments and guitars having such devices and methods for designing and using such devices and guitars representative examples of the present invention.