Tune-o-matic

Tune-o-matic (also abbreviated to TOM) is a name of fixed bridge design for electric guitars. It was designed by Ted McCarty (Gibson Guitar Corporation president) and introduced in the Gibson Super 400 guitar in 1953 and the Les Paul Custom the following year. In 1955, it was used on the Gibson Les Paul Gold Top. It was gradually accepted as a standard on almost all Gibson fixed-bridge guitars, replacing the previous wrap-around bridge design, except on the budget series.

Function

Guitar strings, especially steel strings, are not ideal vibrators. Generally the thicker the string, the shorter the effective length. This refers to the length of string involved in producing a sound, as opposed to the length between the nut and the bridge. Many guitar designs with fixed bridges have the bridge slanted or stepped so that the distance from nut to bridge is larger for thick strings. The Tune-o-matic extends this idea to make the distance adjustable for all the strings, within limits.