Name: Viola caipira.
Type: Lute > Chordophone.
Hornbostel Sachs No#: 321.322.6
Region: South America.
Description: The viola capeira, often simply viola, Portuguese for country guitar. It is a Brazilian ten-string guitar with five courses of strings arranged in pairs. It was introduced in the state of São Paulo, where it is widely played as the basis for the música caipira, a type of folk-country music originating in the caipira country of south-central Brazil.
Origins: The origins of the viola caipira are obscure, but evidence suggests it evolved from the vihuela/viola de mano that Spanish and Portuguese settlers took to the new world. It has also similarities with the 5 course baroque guitar, that elsewhere evolved into the modern guitar.
It is likely a descendant of one of the many folk guitars that have traditionally been played in Portugal. The viola braguesa and viola amarantina, for instance, are two types of ten-string guitars from the north of Portugal, which are closely related to the viola caipira.
Citations: The Online Encyclopedia of Tunings – Viola Caipira