Complex sentence: While playing locally with original content from their demo, they caught the attention of the indie label Obscure Plasma Records and released "Black Screams" EP in September 1991 which was originally their demo and sold 2500 copies worldwide.
Split into simpler sentences: While playing locally with original content from their demo, they caught the attention of the indie label Obscure Plasma Records. Their demo was released as "Black Screams" EP in September 1991, and sold 2500 copies worldwide.