That music column in the CD I went through for the Time Travel Thread gave me inspiration to do a music review. I'm gonna take a look (a listen?) at Metallica. Won't be a comprehensive review, but I just have this gut feeling I'm gonna find something I want to make note of.
I think this will be a short series I'll post in the next week, going on bit by bit. So let's listen some Metallica songs, although I'm gonna try excluding the most played ones.

Lars Ulrich and James Hetfield were the founder, among their first recruits they had Dave Mustain as lead guitarist. What I read about them made the impression that both Lars and James were quite driven musicians with some ideas what music they wanna play. However Mustain was an outstanding musician with written material he already had. Their first album, Kill 'Em All, is largely his work what Lars and James kneaded through, adding or maybe removing here and there, changing lyrics.
A controversy arouse from this fact, because Mustain was booted from the band due to his extreme drinking habit and aggression - still they kept and played his riffs. He gave them so much some of his stuff greets us even from the second album Ride the Lightning.
Ofc, he is credited for his work, but was a long running issue metal magazines liked to pick on, and fans of Megadeth (Mustain's band he founded after he left) and Metallica getting angered by.
The Four Horsemen originally was titled as Mechanix and Mustain featured that original song on the Megadeth album: Killing Is My Business... And Business Is Good!
Jump in the Fire was also largely written by him.
In case of Seek and Destroy he is credited and it is unknown how much of his - the solo for sure -, it is a possibility that this was another already existing song.
For the last one I included (Anesthesia) - Pulling teeth, since I can introduce Cliff Burton with that. He was a great bass player. I read they booted their original bassist because he did not really contribute anything worthwhile just followed. Burton however played a nice solo both Lars and Hetfield noticed, this one they put onto their first album.