Bahia's population has a large proportion of dark-skinned Brazilians who are descendants of African slaves who were brought to Brazil by the Portuguese in the 17th and 18th centuries.
The paradoxical result was that samba was brought back to Bahia from Rio, but now in a highly altered form, and no longer associated with Afro-Brazilians.
Ilê Aiyê's founders aimed to create a music blending influences from the revered Jamaican artists, Bob Marley and Jimmy Cliff, with elements of the older, Bahian style of samba (samba de roda).
All of Ilê Aiyê's lyrics always have political and social content, and typically profile some aspect of African history.
Musically, Ilê Aiyê's major innovations to samba were the addition of a new 3rd surdo playing rapid rolls with two mallets, the addition of a reggae backbeat played by the snare drums (caixas), and the creation of a new clave pattern that is a blend of samba-de-roda clave with a reggae backbeat.
This group was founded as a bloco afro, which is a "Bahian Carnival Association highlighting African heritage through music, dance theater, and art.
The resulting rapid-fire clatter of the repiniques, along with the distinctive driving roll of the 3rd surdo, gives samba-reggae an unmistakable sound.
Olodum had combined the traditional samba with sounds from a number of other Caribbean music genres, including: merengue, salsa, and reggae.
Against this, the high-pitched repiques and caixes filled out the pattern with fixed and repeated rhythms in a slow tempo, imitating the shuffle feel of reggae.
Olodum became progressively more well known, and recorded with Paul Simon, Michael Jackson, Pet Shop Boys and many prominent Brazilian musicians.
Timbalada also developed a rack of 3 surdos and 1 repinique that could be mounted on a stage and played by a single player.
In addition, samba-reggae groups may also play styles derived from the original Bahian samba-de-roda, from its modern urban descendant ("samba duro"), or from axé pop music.
The fourth surdo is tuned very tightly and plays rapid 16th-note rolls with two mallets, which gives samba-reggae its unmistakable rumbling sound.
The repinique may also play loud variations, rolls, and improvisation fills, similar to the role of the third surdo in Rio-style samba.
Most dramatically, the fundos (first and second surdos) frequently take center stage to do elaborate, showy mallet lifts and throws, and tossing their huge drums high overhead.