There are many types of son, of which the "son montuno" is one. The term has been used in several ways. Probably the 'montuno' originally referred to its origin in the mountainous regions of eastern Cuba; eventually, it was used more to describe the final up-tempo section of a son, with its semi-improvisation, repetitive vocal refrain and brash instrumental climax. The term was being used in the 1920s, when son sextetos set up in Havana and competed strongly with the older danzones.