Sound — 9
This is, in my opinion the greatest thrash album ever (not dissing Slayer or Megadeth, there still great). It has everything, speed riffs (Battery, Damage Inc.), slow chugging riffs (The Thing That Should Not Be), shred solos (Disposable Heroes) and slow haunting solos (Orion, Welcome Home (Sanitarium)). This kicks the ass of anything they have put out within the last 15 years.
Lyrics — 9
The lyrics are one of this albums greatest features. There very meaningful and not just about death and violence. for example, "Master Of Puppets" is about the dangers of drug abuse and "Leper Messiah" deals with TV advertising and religions that are just out to get your money. However, for some of the faster songs they do resort to just singing about violence, but this isnt really a problem and they still fit in with the songs.
Overall Impression — 9
It's hard to pick one song that stands head and shoulders above the restbecause there all so good, however in my personal opinion "Welcome Home (Sanitarium)" is the best as it has everything a good metallica song needs, thrashy riffs, killer solos and lyrics that really make you think. the worst song in my opinion would have to be "The Thing That Should Not Be". By no means a bad song but the riff, despite being bludgeoningly brutal and heavy, is repeated a few too many times and eventually gets boring. It doesn't compare to anything they have recorded before or since, which is another reason it's so great, it's utterly unique. Overall a brilliant album and if it was lost I would buy it again in a second.