For someone who was barely a year old when it was released, the importance of Metallica’s debut is difficult to realize. Simply put, Kill ‘Em All was the first album-length release of thrash metal, which would inspire dozens of other bands. Before this album no one else had combined the heaviness of metal with the speed and aggression of hardcore punk and the complexity of progressive rock into this style that is now quite familiar. As the first of its kind, it is essential listening for any heavy metal fan in spite of its flaws.

Several of the tracks are epic compositions, eschewing the verse-chorus-bridge structure that is common in popular music for multiple independent but connected sections. Specifically, “The Four Horsemen”, “No Remorse”, and “Seek & Destroy” are among the finest compositions Metallica ever wrote and representative of the very best of the genre. These songs draw from distinct influences - “Seek & Destroy” is bluesy, while “The Four Horsemen” uses swing rhythms more commonly associated with jazz - but every riff is equally exciting. Hetfield’s rhythm guitar is what makes these songs irresistable, but Cliff Burton’s bass work is also exceptional. For a particular example, listen to the melodic rising line used through the (relatively) low-key interlude in “The Four Horsemen”.

Burton has a showcase on “(Anesthesia) Pulling Teeth”, and makes it clear why the other band members were so interested in his services. Few people have ever managed to use the bass guitar so effectively as a lead instrument. It would not be an overstatement to say that Burton’s solo on this album did for rock and metal bassists what Jaco Pastorius’s debut album did for jazz bassists. That is, it opened an entirely new world of ways in which the instrument could be used.

The rest of the album is not up to the same quality, and has not aged so well as the limits of the new genre were explored. “Whiplash” is notable for its extreme simplicity, speed, and aggression; the song consists of little more than the band pounding out sixteenth-notes at 180 bpm. “Motorbreath”, “Jump In The Fire”, “Phantom Lord”, and “Metal Militia” are not bad songs, but they are each built of just a few riffs and seem like they could have been written by any of the bands that followed Metallica’s lead. The opening rave-up “Hit The Lights” is the only real throwaway track, and serves its purpose well enough.

Kill ‘Em All is not the masterpiece that Metallica would make in its next two albums, but it is a piece of musical history, and one that holds up quite well on its own.