A specific instrumental format of Cuban music developed around 1940, which is derived from earlier ensembles and usually consists of piano, guitar (sometimes), tres, contrabass, bongos, congas, one or more vocalists (who play hand percussion such as maracas and claves), and two to four trumpets.

A specific style of instrumentation developed around 1940, derived from the septeto ensemble, consisting of guitar, tres, contrabass, bongos, three vocalists (who play hand percussion such as maracas and claves), and two to four trumpets. The piano and the tumbadora were added by legendary tres player Arsenio Rodriguez.

Cuban conjunto sprang from the carnival marching bands and combined voices, trumpets, piano, bass, conga, and bongó. Arsenio Rodriguez ran a seminal Cuban conjunto that used the smokey tone of the tres (q.v.) to balance the brass, and over the years conjuntos began adding a trombone or even in New York substituting trombones for trumpets. The chicano conjunto consisted of an accordion lead, guita and/or bajos sexto (q.v.), often bass, and sometimes spoons, with the addition of bongó or other Cuban-derived percussion during the 1960s. Used strictly for instrumental dance music until the 1930s, during the 1940s it became the standard backing for corridos, rancheras, and other vocal forms. The Puerto Rican conjunto, the basic group of jibaro country music,consisted of cuarto, guitar, and güayo scraper, though trumpet and/or clarinet were added at various times, and accordion-led conjuntos playing danzas and waltzes for dancing were not uncommon.