As son moved westard towards urban and cosmopolitan Havana, its music and dance styles grew and evolved. In Havana, influences such as American poular music and jazz via the radio were adopted. The trios gave way to the septets, including guitar or tres, marímbulas or double bass, bongos, claves and maracas. The trumpet was introduced in 1926. Lead singers improvised lyrics and embellished melody lines while the clave laid down the basic 1-2-3, 1-2 beat,
As time passed, musicians began "whitening up" son for the growing tourist traffic in the Havana nightclubs who did not understand the complex African rhythms. Arsenio Rodriguez, one of Cuba's most famous soneros, is considered to have brought son back to its African roots in the 1940s by adapting the guaguanco style to son, and by adding a cowbell and conga to the rhythm section. He also expand the role of the tres as a solo instrument. Rodriguez introduced the montuno (or mambo section) for melodic solos and his style became known as son montuno
In the 1970s and onwards, son montuno was combined with other Latin musical forms, such as the mambo and the rumba, to form contemporary salsa music, currently immensely popular throughout Latin America and the Hispanic world. However, there are still many practioners of traditional son montuno, such as Elias Ochoa, who have recorded and toured widely as a result of the upturn in interest in son montuno since the mid-1990s.