Afro-Cuban rhythm is one of the most influential and widely recognized rhythmic traditions in the world, originating in Cuba during the 19th century. It emerged from the rich cultural fusion of Spanish colonial music and the percussion traditions brought to the island by West African enslaved people — particularly Yoruba, Ewe, and Bantu peoples — as well as Haitian influence following the Haitian Revolution. The word clave (Spanish for "key") is central to this tradition: it refers both to a pair of hardwood sticks used as instruments and to the five-stroke asymmetric rhythmic pattern that serves as the organizing backbone of all Cuban music. This clave pattern, spanning two measures with a 3-stroke side and a 2-stroke side (or vice versa in 2-3 orientation), acts as a temporal key that synchronizes every instrument in the ensemble. The tradition gave rise to foundational genres including son cubano, rumba, mambo, cha-cha-chá, and eventually salsa and timba. In the mid-20th century, Afro-Cuban rhythms profoundly shaped American jazz through figures like Dizzy Gillespie, Mario Bauzá, and Mongo Santamaría, whose composition "Afro Blue" became the first jazz standard built on an African 3:2 cross-rhythm. Typical Afro-Cuban music is played in 4/4, 2/4, or 6/8 time, at tempos ranging from 80 to 160 BPM depending on style, and features a percussion section built around congas, bongos, timbales, clave, maracas, and marimba, layered with piano, bass, and horns. From the clubs of Havana to New York salsa orchestras and Latin jazz ensembles worldwide, Afro-Cuban rhythm remains a living tradition and a cornerstone of modern popular music.