Original sentence: A few new, unambiguously metal bands had commercial success during the first half of the decade—Pantera's Far Beyond Driven topped the Billboard chart in 1994—but, "In the dull eyes of the mainstream, metal was dead".In  In 1991, Metallica released the platinum-selling album Metallicaalso known as The Black Album which moved out of the thrash niche and entered mainstream metal
Edited sentence: In  In 1991, Metallica released the massively successful 16x platinum Metallicaalso known as The Black Album which their sound broke out of the thrash niche and entered mainstream heavy metal A few new, unambiguously metal bands had commercial success during the first half of the decade—Pantera's Far Beyond Driven topped the Billboard chart in 1994—but, "In the dull eyes of the mainstream, metal was dead"