Monochords

275px|thumb|A string, tied at A, is kept in tension by W, a suspended weight, and two bridges, B and the movable bridge C, while D is a pulley|freely moving wheel, density may be tested by using different strings

thumb|An Ektara from Bangladesh

Vietnamese stringed instrument

thumb|Toomba and algoza. The tumbi or toombi (, pronunciation: tūmbī), also called a tumba or toomba, is a traditional musical instrument from the Punjab region of the northern Indian subcontinent. The high-pitched, single-string plucking instrument is associated with folk music of Punjab and presently very popular in Western Bhangra music.

thumb|Psalmodicon from a farm on the island Skorpa, Nordland|Skorpa in [[Helgeland, Norway, with bow and music book in siffernotskrift]] thumb|Psalmodikon from Gagnef, Dalarna, Sweden, made in 1869, originally with three strings thumb|Psalmodikon, played at the School Museum in Djurmo, Dalarna, Sweden The psalmodicon (psalmodikon or salmodikon) is a stringed musical instrument a type of Monochord; the most common variants have a single string. It was developed in Scandinavia for simplifying music in churches and schools, and as an alternative to the fiddle for sacred music. The instrument coul

single-string zither of the rural American South

The duxianqin is a Chinese plucked string instrument with only one string; it is derived from the Vietnamese đàn bầu. Chinese sources describe duxianqin as being an instrument of the Jing (also spelled Gin or Kinh) ethnic group, who are ethnic Vietnamese living in China. It is still commonly played by this ethnic group. Sometimes the body of the instrument is made from a large tube of bamboo rather than wood, which is more common in Vietnam.