Nengón is therefore sometimes seen as the grandfather of son and together with the Changüí is considered one of the prototypes of Son, sometimes referred to as proto-sones or primeval sones as musicologist Danilo Orozco describes them. These styles were developed by Guajiros (Cuban peasants) of predominantly Bantu origin although other rumbitas from different geographical Cuban areas such as Sucu-Sucu from Isla de Pinos are also considered proto-sones in terms of the musical characteristics they share with the style that eventually emerged as Son Cubano. Ultimately, there continues to be widespread disagreement around which particular music styles influenced Son Cubano directly due to the lack of documentation. Even though it is one of the most widespread and important forms of Latin music it is one of the least studied forms according to musicologist Cristóbal Díaz.
The transition into son was marked by aspects such as instrumentation which consisted of clave, maracas and guitar in early forms of the music. Over time, tres, bongos, guiro and bass (such as marímbula, botijo, serrucho, contrabajo and bajo) were added to the mix. The composition of band members changed from early trios and cuartetos to a sexteto in the 1920s through the influence of a band first called Cuarteto Oriental which expanded from maracas (Felipe Neri Cabrera), botija (Guillermo Castillo), claves (Gerardo Martínez) and tres (director Ricardo Martínez). With the addition of band members Antonio Bacallao and Óscar Sotolongo the band re-established themselves under the name Sexteto Típico Oriental adding guitar and bongos into the band. Ricardo Martínez was later replaced by Carlos Godínez at which point the band renamed itself as Sexteto Habanero which went on to popularise its sextet configuration of instruments to the point where their model is now seen as the classical format of the son sexteto. In 1927 a cornet player (Enrique Hernández) was added to the band who was eventually replaced by a trumpet player (Félix Chappottín) bringing the band into the modern septet form and changing the name of the band to Septeto Habanero.
The septeto format using the sexteto Son composition and a cornet or trumpet player was a common feature in Son Cubano in the 1920s and 1930s but later these were replaced by even larger bands called “conjuntos” which added piano, more percussion instruments and trumpets.
