Complex sentence: Cat Ellington is also the founder of the Black Jaguar Music Company (BJMC), which is an independent music publishing house that had originally been founded as Black Jaguar Songs in 1982; the BJMC solely houses and produces her entire body of musical works.
Split into simpler sentences: Cat Ellington is also the founder of the Black Jaguar Music Company (BJMC), which is an independent music publishing house that had originally been founded as Black Jaguar Songs in 1982. And the BJMC solely houses and produces her entire body of musical works.