A string puller for selectively adjusting the pitch of the string(s) of a stringed musical instrument. Each string of the instrument is attached to a respective string puller. Each string puller comprises a pivoting member rotatably mounted on a pivot at a pivot support on the pivoting member. The pivoting member has a knife-edge surface which supports the string such that contact of the string at a first end of the scale ends at said knife-edge surface throughout a normal range of pivoting of said pivoting member. The pivoting member is disposed on a lever for pivoting the pivoting member to adjust the tension on the string.