1943 Arsenio Rodríguez - Oye como dice
xx0x 0xxx 0xx0 xx0x 2-3 son clave
0xxx 0x0x xxxx 0x0x
xxxx 0x0x xxxx 0x0x
xxxx 0x0x xxxx 0x0x
xxxx 0x0x xxxx 0x0x MIDI example
bassist: Nilo Alfonso
source: Emiliano Echeverría

notes: This example takes the bombo-ponche figure (xxx0 xx0x) and moves the bombo forward to the backbeat (xxxx 0x0x), creating a subtle, but distinct change in the flavor of the rhythm. This figure later became the basis for rhythms such as a caballo and pachanga, and of course, timba aficionados will immediately recognize it as the most common breakdown figure for the kick drum (example - source).

Another notable feature of the Oye como dice tumbao is its extended length of 4 claves. Finally, from a purely subjective point of view, this track strikes me as a creative breakthrough in terms of the quantity and intensity of its musical "hooks", which still sound very fresh today.