A metal classic and rightly so, what an album. Heavy when it can, but with quieter intros etc... it's not just full pelt the whole time and it is very listenable. There is excellent virtuosity here but it's all functional. I almost took one point off for the production. A lot of Metallica is about the interlocking of the kick drum and the bass, almost sounding as one instrument giving a solid basis on top of which the guitars and vocals can shine. However, the kick drum sounds quite tinny (I listened on a good stereo) and the bass is... where is the bass? A pity, this album could sound better but I'll still call it a 5 purely for the quality of the music.