Violin where a stopped note sounds a unison or octave with another (open) string, causing it to resonate sympathetically. Students often use these ringing tones to check the intonation of the stopped note by seeing if it is harmonious with the open string. For example, when playing the stopped pitch "A" on the G string, the violinist could play the open D string at the same time, to check the intonation of the stopped "A". If the "A" is in tune, the "A" and the open D string should produce a harmonious perfect fourth. Violins are tuned in perfect fifths, like
Banjo often with a higher string action. The modern five-string banjo is a variation on Sweeney's original design. The fifth string is usually the same gauge as the first, but starts from the fifth fret, three-quarters the length of the other strings. This lets the string be tuned to a higher open pitch than possible for the full-length strings. Because of the short fifth string, the five-string banjo uses a reentrant tuning—the string pitches do not proceed lowest to highest across the fingerboard. Instead, the fourth string is lowest, then third, second, first, and the fifth string is highest. The short