10 GUTSIEST Moves Metallica Ever Made (And Whether They Paid Off)

It's almost impossible to conceive of how much Metallica achieved while staying an "underground" band. Though they never were played on radio and rarely made music videos, they were growing into an arena act alongside some of their hair metal peers. Then again, maybe it was time to embrace the commercial side of things.

Coming off of the monster that was And Justice for All, the band wanted to get back to writing simpler songs. While scouring for producers, the band eventually landed on Bob Rock, whose work included everyone from Bon Jovi to Aerosmith. The pairing definitely was a weird choice, but not one to sharpen pitchforks over either.

For most of the sessions, Rock worked the band into the ground, with one particularly bad day involving him reprimanding Kirk Hammett to reach inside himself to find the solo for "The Unforgiven." The record was not easy to make by any stretch, but in time the Black Album became the most successful metal album ever released.

While some hardcore fans may have felt betrayed by the band's switch to a more accessible sound, songs like "Sad But True" and "Enter Sandman" still showed the metal juggernaut that was lying beneath the surface. Far beyond just a great record, this was the crossover that brought Metallica to the mainstream and got so many young fans interested in metal. The band may have had classics under their belt, but this gamble ended up being their Dark Side of the Moon moment.