The peghead has tuning machines either from the side or from the back.

On instruments equipped with tuning machines, violins and guitars, for example, a key is part of a tuning machine.

With other instruments, zithers and drums, for example, a key is essentially a small wrench used to turn a tuning machine or lug.

A removable black aluminium panel below the keys provides access to the tuning machines.

Other changes included standard right-angled tuning machines, and the addition of a chrome bridge cover.

Keith's invention made the extra hardware unnecessary, replacing two of the tuning machines already on the banjo - a more elegant solution.

Also, most dan bau now have modern tuning machines, so the base pitch of the string can be adjusted.

The key on the tuning machine turns a metal worm, which drives a worm gear that winds the string.

The six extra holes in the headstock for the tuning machines were filled and veneered over.

However, some guitars (such as Steinbergers) do not have headstocks at all, in which case the tuning machines are located elsewhere, either on the body or the bridge.