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
Violin technique other strings are not so equipped. The A string is tuned first to a reference pitch source such as a tuning fork or, in most orchestras, the oboe, typically to 440 Hz, although some orchestras tune to another standard A such as 442, or even as high as 445 or 446 Hz to produce a brighter sound. Early music groups interested in authentic performance may use a lower standard A. When playing with a fixed-pitch instrument such as a piano or accordion, the violinist must tune to accommodate that instrument. The other strings are then tuned to the A in