Bomba and plena are both Afro-Puerto Rican musical styles. Bomba is an African-derived music and dance style developed in coastal towns of Puerto Rico, especially Loiza Aldea, among large communities of black sugar-cane millworkers. Traditionally it was performed at social gatherings with an ensemble of one or two low-pitched barrel-shaped drums providing a fixed rhythmic pattern, an improvisatory higher-pitched one, maracas and a pair of sticks, which tap out a fixed organising rhythmic timeline on the side of a drum or any resonant surface. Bomba was modernised during the 1950s by Rafael Cortijo and his vocalist Ismael Rivera. Plena is a topical and often satirical urban song form akin to Trinidadian calypso that emerged in the southern coastal town of Ponce during the First World War. Said to derive from songs introduced to Ponce by immigrants from St Kitts or Barbados. A typical plena rhythm section features the pandereta, a tambourine without the cymbals. Jíbaro music is the Spanish derived music composed and performed by Puerto Rican country folk. Typically played by small groups comprised of cuatros, the emblematic jíbaro instrument, and guitars, the lead singer is expected to improvise décimas, ten-line verses. The cuatro player Yomo Toro is an archetypal jíbaro musician. - John Child