There are few forces quite as powerful as the metal riff. Repetitive, infectious, and iconic, every metalhead has a riff that has worked its way into their hearts and never left. This metallic staple is technically defined as a short, repeated tune, and it often emerges as the most attributable signature to a song.

For the countless riffs that are instantly identifiable, there are a handful that are undoubtedly some of the most iconic. They are pieces of music that bring people to tap their feet, hum along, or drum their fingers against the table in time. They call on new musicians to pick up an instrument and try to replicate their splendor. While it’s impossible to look at the history of metal music and declare any definitive winners in riff-based excellence, this short list captures some of metal’s most timeless and iconic riffs.

15. White Zombie – “Thunder Kiss ‘65”

“Thunder Kiss ‘65” is a time capsule contained in a riff. It has grit, it has charisma, and it has the teeth that allowed it to sink deep into the public consciousness. There are few tracks from the time that developed such an instantly classic sound and even fewer that did so with such a massive hook. From the opening note to the chorus, this is a tune that builds up the essential sound structure effortlessly. Whether fans were first introduced via the iconic music video when it first aired, or during its more recent surges on social media, it is impossible to forget the guitar that built one of White Zombie’s most essential tracks.

14. Rage Against The Machine – “Bombtrack”

If you’re looking for an opening riff that takes your breath away, look no further than Rage Against The Machine and their ever-spirited “Bombtrack.” This furious hook, still so carefully measured with its impact, lit a flame that would burn for decades. The riff that builds out “Bombtrack” holds steady as the song shifts from ominous to angry. Each repetition adds itself to the rawness of vocalist Zack de la Rocha and his recitation of the chorus. It’s also a display of the talent that would propel Tom Morello to global fame and would grant him unending acclaim for his role as Rage AgainstTthe Machine’s guitarist.

13. Mastodon – “Blood And Thunder”

The first line in the novel Moby Dick (1851) is “Call me Ishmael” - a statement that immediately sets the tone for the voyage to come. This is echoed in the guitarwork of Brent Hinds and Bill Kelliher on “Blood And Thunder.” “Blood And Thunder” serves as the opening track of Mastodon’s sophomore album, Leviathan, an opus named for its concepts grounded in the Melville novel. In Mastodon’s riffing there’s a sense of immediacy and gravitas with a similar forcefulness to that of the eponymous beast. The song - and the record as a whole - could be described as a whale of a time.

12. Gojira – “Flying Whales”

As if there were not enough riffs to sustain the ravenous whales of “Blood And Thunder,” Gojira takes this concept to the next level on their exemplary “Flying Whales.” Part of what makes the foundational riff so iconic is Gojira’s commitment to its isolation, and in this isolation, its excellence truly shines. For more than two minutes the riff repeats without interruption, painstakingly building the atmosphere and breadth of the experience to come. The introduction, and the bones of the riff it is built upon, are like none other in not just progressive metal, but metal as a whole. And while some songs may have already reached their conclusion by the time other instruments and vocals truly join the fray, many of Gojira’s fans say that this riff could have filled the entire eight-minute song without drawing complaints.

11. Opeth – “Master’s Apprentice”

This mammoth of a track traverses soundscapes from ethereal beauty to the terror of the dark, and the main guiding force is an onslaught of furious riffage, including its opening splendor. Repeating more than a dozen times, this opening tune pulls its listeners headfirst into the start of an unparalleled sonic journey. While many iconic riffs are motifs that begin as hooks and build into an impactful chorus, the riffs that make “Master’s Apprentice” so noteworthy are embedded with particular profundity. “Deliverance” is one of Opeth’s most accomplished studio outings, and at more than ten minutes long, the riff-packed “Master’s Apprentice” has some of the most emblematic passages from the band’s discography.

10. Black Sabbath – “Iron Man”

“I am Iron Man.” There are few Black Sabbath songs that are so wholly revered, and few words that offer such an exhilarating introduction to aural bliss. But even more iconic than its title and chorus is the riff that bestows “Iron Man” with its eminence. This is the epitome of metal’s mind-bending power. While modern genre classification would drag this slow, ominous tone into the realm of stoner metal, its prescient quality quickly defined the scope of possibility in heavy music. No words are necessary for understanding, no explanation required for enjoyment: simply surrender to the darkness that has infiltrated every breath of Tony Iommi’s guitar.

9. Lamb Of God – “11th Hour”

Heavy, relentless, and punishing, the riff that binds “11th Hour” together is veritable sonic fire. Matched in perfect time by a percussive assault, the fierce guitar tones that Lamb Of God has borne into making “11th Hour” nothing short of ardent fury. It features a thoughtful balance between technical demands and hook-driven infectiousness. Part of the allure is its consistency, for as other elements of the track evolve and transcend, the riff provides an undoubted grounding effect. Resonant with its riff and otherwise, Lamb Of God truly made something special with “11th Hour.”

8. Machine Head – “Davidian”

The intro riff on “Davidian” has been heralded as one of the best in heavy music by musicians and fans alike. Its power and unmoving might set the stage for the furious breakdown to come, and it is the epitome of excellence for its time. In an era where heavy music was gearing up to conquer the world, “Davidian” and its opening riff had an absolute chokehold on perfection. Another example of striking the balance between groove and brutality, “Davidian” is a crown jewel in Machine Head’s discography, and has an ambitious flavor that is owed to its signature riff.

7. Dio – “Holy Diver”

“Holy Diver” is as much a song as it is a feeling, and that feeling is driven by the unmistakable guitar theme that permeates its essence. Of the legacy that Dio has left behind, “Holy Diver” is an immutable part, as is the delectable songwriting that makes this track so infectious. With its deep and resounding tones against Dio’s impassioned voice, it brings the very depths of the midnight sea to the listener with each note. As every repetition calls upon new emotion, it’s impossible to sit still, or even refrain from nodding one’s head. There’s a reason why metalheads young and old still throw up the horns and celebrate this masterpiece.

6. Megadeth – “Symphony Of Destruction”

Countdown To Extinction is an essential highlight in the Megadeth discography, and “Symphony Of Destruction” is an immutable cornerstone to this exemplary album. The central riff is the adrenaline-fueled blood of this well-beloved song, and more than just being memorable, it is the perfect backdrop to one of the most vivid solos that Megadeth has ever conjured. There is a simplicity to its structure, but the palm-muted closing line and dissonance elevate simplicity to the extraordinary.

5. Sepultura – “Territory”

Immovable and uncompromising, “Territory” is a tempest of thrash and furor. Sepultura had spent their earlier albums truly coming into themselves as a heavy act, but with Chaos AD - and particularly “Territory” - they had established themselves as a force to be reckoned with. The agitated and unending march of “Territory” and its guitar has ensured that it was not only an instant hit, but remains a staple at Sepultura concerts today. This riff grits its teeth and takes the rhythm section in a no-holds barred match for the listener’s attention. It wavers from subtle to overt, and each step of the way it works its way further into the song’s bones. The thrash-driven riffage sets “Territory” alight with welcome trepidation, and cements its legacy in the genre.

4. AC/DC – “Back In Black”

A riff that lives forever in the honor of a man who would never hear it. “Back In Black,” from the album of the same name, was written as a tribute to former AC/DC singer Bon Scott. Scott had died in the year before the album’s release, and this song is one that both celebrates his contributions and mourns his absence. Not only is “Back In Black” a song that lives on as one of the most memorable songs in rock, but it is one of the most instantly identifiable by its riff alone. The motif is one that clings to every verse, every chorus, and it continues to stand out from the fray of its time as something particularly phenomenal.

3. Slayer – “Raining Blood”

Beneath the static and percussive fury that dominate its oppressive atmosphere, the main riff on “Raining Blood” is even more unforgettable and momentous. This is easily Slayer’s most famous song, and for good reason - aside from the insatiable fever of Tom Araya’s screaming, there is the earth-shattering riffage from guitarist and songwriter Jeff Hanneman. The speed and metallic energy don’t ease up for a moment. More than three decades of live shows have brought “Raining Blood” to life, and a thunder of cheers reliably rise up alongside it. “Raining Blood” proves that Hanneman was a master of his craft, and that he was a performer whose songwriting skill was always destined to outlive him. Blood pours from the sky, and timeless riffs from Hanneman’s fingers, coalescing in the enduring “Raining Blood.”

2. Metallica – “Sad But True”

“Sad But True” is memorable for its sheer grit and abrasiveness. This is particularly true of its iconic riff, which proceeds in an unending onslaught of heavy punishment, a new punch to the gut with each repetition. For a song whose themes are grounded in seeing the darker sides of oneself, there is no instrumental interpretation that could be truer than that within “Sad But True.” The mind-blowing impact of its intentional pacing, mind-bending solo, and massive chorus, would be impossible without the violent riff to tie it all together. It is both catchy and solemn, its energy tempered by its somberness. When “Sad But True” plays, it’s impossible to resist the riff as it grabs the listener by the hand and pulls them headfirst into Metallica’s overpowering and heavy proposition.

1. Pantera – “Walk”

It may not be the heaviest, fastest, or most technical display, but no list of iconic riffs would be complete without perhaps the most enduring of all: Pantera’s “Walk.” It is groove-oriented, and almost inebriating with its pointedly aggressive atmosphere. There’s no doubt that the talented guitarist behind the strings is responsible for just how timeless “Walk” became. Dimebag Darrell is considered one of the greatest guitarists of metal history, and “Walk” is exceptionally demonstrative of his magnetic style of playing. The sheer attitude that seeps from “Walk” is not easily replicated, because this is a riff that requires more than technical skill and understanding: it needs a particular touch, an understanding of Pantera’s driving forces. That feeling is one Pantera’s original guitarist understood intimately, and as the band shifted their focus in songwriting to even greater groove elements, “Walk” highlighted an ascendancy that was possible with the right guitarist on hand.