By Jon Wiederhorn

For thrash metal fans, July 25 is arguably as significant as independence Day. It was a major turning point for the genre, one that influenced a generations of musicians to up their game and speed up their chops. It was the day Metallica released their first album Kill 'Em All.

Metallica's 1982 demo "No Life 'Til Leather" was already legendary in the underground, and their song "Hit the Lights" had been featured on the compilation Metal Massacre that same year. But Kill 'Em All, was the first definitive thrash album, featuring 10 bruising songs that combined the crunch and catchiness of New Wave of British Heavy Metal bands like Judas Priest, Iron Maiden, and Diamond Head with the speed and ferocity of Motörhead and early hardcore.

While it was released 30 years ago, the influence of Kill 'Em All still resonates, and Metallica continue to play album tracks including "Whiplash," "Seek & Destroy," and "No Remorse" in concert. That's because Kill 'Em All has aged incredibly well, sounding just as gripping and fiery as when it was first came out on vinyl. That's a major statement for any release, but even more impressive considering Metallica recorded the album with Paul Curcio, whose only previous production credit was for the Doobie Brothers, and he wasn't exactly an icon of metal. Fortunately, Metallica were well-rehearsed, unified, and ready to destroy.

"We were up in Rochester, New York [at Music America Studios] for five or six weeks," drummer Lars Ulrich told Yahoo! during a recent interview at Comic-Con. "It was our first recording experience and we were so psyched and appreciative with the fact that we were making a record, and we were psyched about the way it was sounding. We had some good times with some locals that we befriended and there was a great unity."

For Ulrich, part of the magic of Kill 'Em All stemmed from the band's youthful enthusiasm – the type of zeal that can only be generated by inexperienced but ambitious musicians seeking to prove themselves. "There was a beautiful innocence and a wide-eyed [excitement]," Ulrich said. "[We were] just trying to figure it all out – a bunch of kids that just got out of the house, and I think that energy is captured in the record."

At the same time, Ulrich recalled being frustrated by the budget Megaforce Records had for the band and the limitations that put on their creative process. "We weren't allowed to come in and listen to our own mixes because we were running out of time, and they figured if the band members came in and listened to their own mixes maybe it would cost more," Ulrich said. "You look back at those kinds of things with mixed emotions."

Listen to Kill 'Em All on Spotify: