Musi people

Musi people (Musi: ) are indigenous ethnic group native to the Musi regions (the regencies of Musi Banyuasin, Musi Rawas, North Musi Rawas, and Banyuasin) in the southeastern Sumatra, Indonesia. They speak the Musi language and share common history and culture.
Language.
Musi language is the first language of Musi people who natively lives at the Babat Toman, the Sungai Lilin, the Bayung Lencir, and the Sekayu districts of Musi Banyuasin, also in the Banyuasin III district of Banyuasin Regency. It is also spoken by the Musi diaspora as the second language in the neighbouring regions; which covering the area of the Banyuasin I, the Banyuasin II and the Talang Kelapa districts of Banyuasin, the Ulu Musi district of Empat Lawang Regency, as well as in the North Musi Rawas Regency generally.
Dialects and varieties.
Dialectologists identify that there are at least two main dialectical groups of Musi language, namely the Sekayu Musi and Duson Musi. 
Sekayu Musi.
Eventhough Sekayu classified as part of the Musi languages, however it is not the native language of Musi people, but Sekayu people instead. Sekayu Musi predominantly spoken by the Sekayu people at the Sekayu district of Musi Banyuasin Regency in South Sumatra. Hence, due to its significant differences compared to Musi people in terms of ethnolinguistic historical background, some of Sekayu people disagree with these classification and rather identified their native language as 'Sekayu language' instead. The name of "Sekayu" itself seen (by Sekayu people) as valuable term that shouldn't be mixed with another entity. 
Doson Musi.
the Doson Musi which literally means "rural". Accordance to its name, the Doson Musi predominantly spoken by Musi people who lived in the rural areas of Musi Banyuasin and Musi Rawas regencies, hence the Doson Musi oftenly seen or regarded as the 'rube' variety of Musi language.