Various kinds of members are located on the body of an electric guitar, and strings are supported by the members at predetermined positions along the longitudinal direction. The strings are adjusted by a fine-tuning element and a harmonic tuning element. A base plate is pivotally supported on the guitar body. Each of saddles is rotatably coupled to one of saddle holders, the position of which can be adjusted in the longitudinal direction of the strings, and corresponds to one of the strings. Each saddle contacts the corresponding string at a predetermined point. Each string holder, which is located in one of the saddles, holds the corresponding string at a part that is below the contact point of the string. The fine-tuning element fine-tunes each string by changing the rotational angle of the corresponding saddle without actually changing the contact point of the corresponding string. The harmonic tuning element adjusts the position of each saddle holder in the longitudinal direction of the strings. A manipulation portion, which is located on the harmonic tuning element, tunes the harmonic of each string at a position above the base plate while the string is held by the associated string holder.