Berlioz's "Symphonie Fantastique" is pretty metal: https://youtu.be/5HgqPpjIH5c

https://en.wikipedia.org/wiki/Symphonie_fantastique

One specific part of this is the fourth movement: IV. "Marche au supplice" (March to the scaffold)

Convinced that his love is spurned, the artist poisons himself with opium. The dose of narcotic, while too weak to cause his death, plunges him into a heavy sleep accompanied by the strangest of visions. He dreams that he has killed his beloved, that he is condemned, led to the scaffold and is witnessing his own execution. The procession advances to the sound of a march that is sometimes sombre and wild, and sometimes brilliant and solemn, in which a dull sound of heavy footsteps follows without transition the loudest outbursts. At the end of the march, the first four bars of the idée fixe reappear like a final thought of love interrupted by the fatal blow.

Berlioz claimed to have written the fourth movement in a single night, reconstructing music from an unfinished project, the opera Les francs-juges.[8] The movement begins with timpani sextuplets in thirds, for which he directs: "The first quaver of each half-bar is to be played with two drumsticks, and the other five with the right hand drumsticks". The movement proceeds as a march filled with blaring horns and rushing passages, and scurrying figures that later show up in the last movement.