A headstock or peghead is part of a guitar or similar stringed instruments such as a lute, mandolin, banjo, ukulele and others of the lute lineage. The main function of a headstock is to house the pegs or mechanism that holds the strings at the "head" of the instrument. At the "tail" of the instrument the strings are usually held by a tailpiece or bridge. Machine heads on the headstock are commonly used to tune the instrument by adjusting the tension of strings and, consequentially, the pitch of sound they produce.