A more developed style (Arsenio Rodríguez in the 1940s), emphasizing call-and-response, montuno sections, and heavier rhythm — this is the direct ancestor of salsa. Instruments:
👉 Larger conjuntos (bigger ensembles), strong rhythm section.
In the 1940s Arsenio Rodríguez became the most influential son musician. He expanded the line-up with congas, piano and extra trumpets: the conjunto. These larger groups displaced the older sextetos and septetos.
The shape of son montuno, a song followed by an open montuno, is the basis of later salsa in New York and of Cuban songo and timba.
In son montuno the weight lies on the montuno, and that is where most of the dancing happens. The steady call and response gives you something to hold on to: a new coro is often a new moment in the dance.