This is a very nice cover of Blackened from “…And Justice For All” by testament19. Here is some classic info about this album from wiki:

The song structures on …And Justice for All were so complex that the band apparently had some difficulty reproducing the songs precisely for their Damaged Justice tour shows. The band stated many times in subsequent years that this kind of difficulty was the primary reason for the relatively simpler song structures on their next album, Metallica. Hammett said: “One day after we played ‘Justice’ and got off the stage one of us said, ‘we’re never fucking playing that song again.’”