"In Afro-Cuban folkloric genres the triple-pulse (12/8 or 6/8) rumba clave is the archetypal form of the guide pattern. Even when the drums are playing in duple-pulse (4/4), as in guaguancó, the clave is often played with displaced strokes that are closer to triple-pulse than duple-pulse. John Santos states: "The proper feel of this [rumba clave] rhythm, is actually closer to triple [pulse].”
Conversely, in salsa and Latin jazz, especially as played in North America, 4/4 is the basic framework and 6/8 is considered something of a novelty and in some cases, an enigma. The cross-rhythmic structure (multiple beat schemes) is frequently misunderstood to be metrically ambiguous. North American musicians often refer to Afro-Cuban 6/8 rhythm as a feel, a term usually reserved for those aspects of musical nuance not practically suited for analysis. As used by North American musicians, "6/8 clave" can refer to one of three types of triple-pulse key patterns...
Triple-pulse standard pattern:
When one hears triple-pulse rhythms in Latin jazz the percussion is most often replicating the Afro-Cuban rhythm bembé. The standard bell is the key pattern used in bembé and so with compositions based on triple-pulse rhythms, it is the seven-stroke bell, rather than the five-stroke clave that is the most familiar to jazz musicians. Consequently, some North American musicians refer to the triple-pulse standard pattern as "6/8 clave."
Triple-pulse rumba clave:
Some refer to the triple-pulse form of rumba clave as "6/8 clave." When rumba clave is written in 6/8 the four underlying main beats are counted: 1, 2, 1, 2.
1 & a 2 & a |1 & a 2 & a ||
X . X . . X |. X . X . . ||
Claves... are not usually played in Afro-Cuban 6/8 feels... [and] the clave [pattern] is not traditionally played in 6/8 though it may be helpful to do so to relate the clave to the 6/8 bell pattern—Thress (1994).
The main exceptions are: the form of rumba known as Columbia, and some performances of abakuá by rumba groups, where the 6/8 rumba clave pattern is played on claves.
Triple-pulse son clave:
Triple-pulse son clave is the least common form of clave used in Cuban music. It is however, found across an enormously vast area of sub-Saharan Africa. The first published example (1920) of this pattern identified it as a hand-clap part accompanying a song from Mozambique."