Musical tuning to the fundamental note of the unstopped, full string. The strings of a guitar are normally tuned to fourths (excepting the G and B strings in standard tuning, which are tuned to a third), as are the strings of the bass guitar and double bass. Violin, viola, and cello strings are tuned to fifths. However, non-standard tunings (called scordatura) exist to change the sound of the instrument or create other playing options. To tune an instrument, often only one reference pitch is given. This reference is used to tune one string, to which the other strings are tuned in the
String (music) core of the string. Bowed instrument strings, such as for the violin or cello, are usually described by tension rather than gauge. Fretted instruments (guitar, banjo, etc.) strings are usually described by "gauge"—the diameter of the string. The tone of a string depends partly on weight, and, therefore, on its diameter—its gauge. Usually, string manufacturers that don't describe strings by tension list string diameter in thousandths of an inch (0.001 in = 0.0254 mm). The larger the diameter, the heavier the string. Heavier strings require more tension for the same pitch and are, as a consequence, harder to press down