Palm-Wine Music is a traditional West African popular music genre that developed along the coastal regions of present-day Ghana, Sierra Leone, Liberia, and Nigeria in the late nineteenth century. The genre has various origins, but primarily palm-wine music ties back to native musical traditions that were introduced to imported instruments, particularly the guitar. Palm-wine music is widely regarded as the foundation of many modern-day popular music styles. It evolved among the Kru people of Liberia and Sierra Leone, who used Portuguese guitars brought by sailors, combining local melodies and rhythms with Trinidadian calypso to create a "light, easy, lilting style". It would initially work its way inland where it would adopt a more traditional style than what was played in coastal areas. It would eventually gain popularity after Sierra Leone musician Ebenezer Calendar recorded songs in the 1950s and 1960s and continues to hold a small amount of that popularity.