Yes, these songs may sound a bit dated in sound quality as they were recored possibly before you were born. And worse than that, if you watched the music videos of a few of these songs, you could possible (and understandably) reject the music as a whole. So, get past all that, alright? And if you're worried about Satan creeping into your brain just from listening, stop. He's already there.
The Songs:
Dio: "Holy Diver"
Ignore the 10 minute interlude and move straight to the metal. For some reason, one of the key fathers of Heavy Metal, Ronny James Dio, decided it would be a good idea to add wind sounds before the song. To me, that doesn't really make sense, but then again, neither do the lyrics. So, the song is conceptually consistant and perfect. And rockin', too.
Iron Maiden: "The Trooper"
This lightning quick tune is one of the earliest face-melters. With galloping palm mutes, "The Trooper" chugs along laying waste to everything along its path, just like the cowboys in the video. And speaking of the video, the Brits had no idea how dated their wardrobe would be 30 years later. A word of caution: Iron Maiden and Bruce Dickinson are not responsible for any broken property caused by someone listening to their music or by Bruce's glass-shattering vocals.
Slayer: "South of Heaven"
Ah, the first hint of the Devil. Get passed it. It's just music. Anyhow, as it begins we are greeted by an ominous solo guitar which is finally met with its harmonious twin. Drums. Heavy, pounding drums. Then, a methodic chug-chug-chugging which eventually turns into a Blitzkrieg. Throughout the song, this on-and-off again pattern occurs. At the end, you're covered in sweat...at least you hope it's sweat.
Judas Preist: "Breaking the Law"
Let's get this out of the way, first: Rob Halford is gay. Now we can move on. Far less heavier than the song above, but the riffs don't lose points for the lack of weight. Look, it was 1980. That was nearly as heavy as it got then. And guess what. The song still holds strong today. It's a helluva lot closer to rock 'n' roll than Billy Joel's "It's Still Rock and Roll to Me", which reached #1 Billboard status that year.
Slipknot: "Before I Forget"
No build up. No foreplay. This song takes flight from second 0:00. And for those who are unaware of this fact, "GO!" is shouted in a deep, guttural growl seventeen seconds from takeoff. This song is more of a march. Not like in high school football games. Rather, it's more like Sherman's March to the Sea-razing buildings and torching everything that's flammable.
If you've heard some or all of these songs, good. You're on the right path. If not, you've not strayed too far. I don't expect you to become a full-fledged metalhead just from these five songs. It just may not be your bag and that's okay. But the next time you need to blow off some steam, remember these songs as well as "Walk" by Pantera. 15 minutes later, you're back at peace with the world again.