Jíbaros are small farmers of primarily Hispanic descent who constituted the overwhelming majority of the Puerto Rican population until the mid-twentieth century. They are traditionally recognized as romantic icons of land cultivation, hard working, self-sufficient, hospitable, and with an innate love of song and dance. Their instruments were relatives of the Spanish vihuela, especially the cuatro — which evolved from four single strings to five pairs of double strings — and the lesser known tiple. A typical jíbaro group nowadays might feature a cuatro, guitar, and percussion instrument such as the güiro scraper and/or bongo. Lyrics to jíbaro music are generally in the décima form, consisting of ten octosyllabic lines in the rhyme scheme abba, accddc. Décima form derives from 16th century Spain. Although it has largely died out in that country (except the Canaries), it took root in various places in Latin America—especially Cuba and Puerto Rico—where it is sung in diverse styles. A sung décima might be pre-composed, derived from a publication by some literati, or ideally, improvised on the spot, especially in the form of a “controversia” in which two singer-poets trade witty insults or argue on some topic. In between the décimas, lively improvisations can be played on the cuatro. This music form is also known as "típica" as well as "trópica".