Soul of a New Machine, Fear Factory's first nationally released album, introduced them to the metal world as a brutally heavy death metal act with a few post-hardcore touches.

Produced by Colin Richardson (Carcass, Napalm Death), that album was the necessary tool that would set the pace for the remainder of their career.

But the first album they ever recorded was actually Concrete, a much different beast than the record that they became known for.

Produced by a young Ross Robinson, this is an important record for both artists.

In what would be the very first album he ever helmed, Robinson's approach takes some of the sludge out of the mix and brings up the elements that keep it vital and interesting.

The discordant guitars, clear vocals, movie samples, and monstrously distorted bass are the primary elements of the disc, taking away Richardson's insistence on chunky guitars and strong percussion.

This works in the band's favor much more than against it, although the drums are buried too far into the mix to be appreciated.

And singer Burton C.

Bell sounds amazing here, jumping from the beautifully mournful moans on "Echoes of Innocence" to a horrifying yelp on "Self Immolation" that doesn't even sound human at times.

But this is the better album, coming off like a woefully lost Helmet/Morbid Angel jam session more than a debut album from an unknown L.A.

metal band.

Why amazing songs like "Echoes of Innocence" and "Dragged Down by the Weight of Existence" were left off the initial release is a mystery.

They still sound just as powerful and unique as they did in 1991.

And anyone looking for the seeds of the late-'90s rap metal movement need look no further than "Sufferage" to see where Robinson first captured this unique tension three years before he would apply it to Korn.

When most bands of this era were still insistent on the traditional death metal sound, Fear Factory proves on this lost gem that they were looking way ahead of the pack.