- Rodney Slatford
A mechanical device for facilitating the tuning of strings. Machine heads are most commonly found on double basses, guitars and other plucked instruments, although before the early 19th century strings were almost invariably secured to tuning pegs on these instruments without mechanical assistance.
Early methods of holding a string at pitch can be traced back to 17th- and 18th-century trumpets marine. A ratchet and pawl, sometimes in combination with a wooden peg or worm gear, was employed to prevent the string slipping (for illustration ...