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
Viol for the lowest-pitched bass strings on viols, and on many other string instruments as well. Viols are fretted in a manner similar to early guitars or lutes, by means of movable wrapped-around and tied-on gut frets. A low seventh string was supposedly added in France to the bass viol by Monsieur de Sainte-Colombe (c. 1640–1690), whose students included the French gamba virtuoso and composer Marin Marais. Also, the painting (1618) by Domenichino (1581–1641) shows what may be a seven-string viol. Unlike members of the violin family, which are tuned in fifths, viols are usually tuned in fourths with a major