When four weird blokes from Birmingham formed the blues-rock band Earth in the late 60s, it’s unlikely that they thought they would go on to inform basically the rest of rock history – but that’s exactly what they did. The world has Birmingham to thank for heavy metal, as well as Cadbury’s chocolate and the Balti Triangle.

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Black Sabbath’s monolithic influence on all things heavy cannot be overstated. However, they were ultimately a product of their time – an inevitable musical comedown as the optimism of the 1960s crumbled.

Young hopefuls of the late 60s had to reconcile with the fact that the countercultural movements of the past decade had essentially failed. The Vietnam war raged on. The hippie communes had either collapsed or taken a dark turn. As veterans returned to the US, the stark reality of the Vietnam war came with them. In the UK, young men feared they too would be drafted. The end of the conflict was nowhere to be seen. And in the working-class suburbs of Birmingham, Flower Power was particularly hard to swallow: the future looked like one thing, and that was a job in a factory.

And so Black Sabbath’s four original members – Tony Iommi, Geezer Butler, Bill Ward and Ozzy Osbourne – turned to music as an escape. Their early work – first as Polka Tulk Blues Band and later as Earth – was mostly derivative of British blues greats in the vein of Cream and the Yardbirds. But it was the combination of this heavy blues-rock with an occult aesthetic, an ominous atmosphere and a much-needed name change that truly resonated with the times, and still resonates today. We owe the creation of countless guitarists to Tony Iommi’s thunderous, downtuned riffs and deft but expressive soling. Here’s why.

10. Fairies Wear Boots (Paranoid, 1970)

Fairies Wear Boots’ intro riff is weird. Really weird. The delayed stereo panning that starts the song is plenty trippy, and makes for an excellent closer to Paranoid – a palette-cleanse from the straightforward heaviness of the majority of the record, albeit not as relaxed as Planet Caravan. It shows just how Sabbath helped turn the 1960s into the 1970s – here we have the kind of hallucinogenic imagery you might find in technicolour psych rock, but with a considerably darker bent. If Sabbath were the bad-trip counterpart to a decade of wide-eyed, optimistic drug-taking, their song about acid was always going to be a lot more, er, paranoid, than something like Lucy In The Sky With Diamonds.

9. Snowblind (Vol.4, 1972)

By the time of Vol 4, Black Sabbath’s daily life was a far cry from the industrial grimness that birthed their earliest, bleakest material. The excesses of stardom has resulted in all four members developing quite the fondness for cocaine, making Snowblind the band’s second drug ode after Sweet Leaf. Given the change in substance, it’s perhaps no surprise that Snowblind is a frenetic, riff-packed track that’s a fair bit more driving and busy than the laconic Sweet Leaf. The arpeggiated open chords that turn the main riff around are a perfect addition to Sabbath’s tried-and-true formula of shifting power chords around the minor pentatonic scale.

8. Planet Caravan (Paranoid, 1970)

Planet Caravan is a perfectly-placed change of pace within Paranoid, one that made good response to accusations that Black Sabbath were essentially “Cream, but for idiots”. The relaxed soundtrack to interplanetary eloping features a brilliant, jazzy solo from Iommi – one that bears all the more significance when you take into account his history.

The story of the industrial accident that severed the tips of Tony Iommi’s fingers and almost made him give up on music altogether has been told time and time again. But it’s important to remember that it was a Django Reinhardt record that convinced him that all was not lost – Reinhardt was able to become an iconic jazz guitarist, despite having lost the use of two of his fretting hand’s fingers in an accident. Planet Caravan’s relaxed, jazzy lead playing is a fitting tribute to Reinhardt, and a reminder that we arguably owe the band’s whole existence to him.

7. Supernaut (Vol.4, 1972)

This oh-so-simple riff is one Sabbath’s catchiest – a straightforward headbanger with a relentless intensity and thick, layered guitar tone. Iommi was never afraid to double-up, and the crunchy harmonies that poke their heads through the many layers of guitars definitely showed that Sabbath were beginning to be comfortable exploring beyond their early grimness. It’s perhaps unsurprising that this track found a second hit as a dance record, thanks to a cover by Ministry side project 1000 Homo DJs in 1990.

6. Heaven And Hell (Heaven And Hell, 1980)

Some dispute how well Ronnie James Dio’s voice worked with Sabbath. A song like Heaven And Hell stakes a good claim for the reverse. While the sound is cleaner, the rough edges of industrial misery all but sanded off, the riffs are still quintessentially Sabbath – there’s hints of Snowblind in the main riff, War Pigs in the verses, and the solo section lets Iommi do what he does best. But the cleaner sound and more driving, traditional-heavy-metal songwriting suits Dio’s voice all the better – he would never be able to conjure up the satanic wails of the earliest Sabbath, so Heaven And Hell instead makes room for his operatic belts.

Iommi and Butler’s chosen tuning of D♯ standard also marked a new sound for the band: not plumbing the doomy depths of C♯ standard as with Vol 4, Master Of Reality and Sabotage, but also a half-step away from the radio-friendly E-standard hard-rock of Technical Ecstasy and Never Say Die.

5: Electric Funeral (Paranoid, 1970)

Other than seeing one being carried onto the stage at a local open-mic, has a wah pedal ever conjured up so much fear? The warbling, nasal riff perfectly underpins a track about global atomic destruction, with the main verses’ descending terror.

Electric Funeral is also a great example of how Sabbath combined the groovy blues-rock they cut their teeth on with the doomier, bleaker material – while the bookends of the song conjure nuclear destruction and Book Of Revelation-style end-times, the middle section kicks into a romping, bluesy breakdown. Talk about whiplash – and not just from the headbanging.

4. War Pigs (Paranoid, 1970)

While War Pigs bears some classic early-Sabbath clunkiness (yes, Ozzy, “masses” does indeed rhyme with “masses”), this isn’t Ozzy’s GCSE English exam, it’s Greatest Guitar Moments. War Pigs has those aplenty. From the opening salvo of droning strings to the spaced out verses, the groovy breakdowns, the killer solo, the oddly triumphant ending section (entitled Luke’s Wall on some releases), it’s impressive how much stuff the band threw into this song without it becoming bloated, a feat arguably chalked up to their countless hours jamming out extended versions of tracks when they first started playing live – the beautifully simple production capturing the feel of four musicians playing in a room, and never letting you get bored of a riff.

3. Into The Void (Master of Reality, 1971)

If Sabbath’s first two albums are a rough sketch of doom metal, Into The Void is a 400-page design document for the genre. The lower tuning (down to C♯ standard) gives tremendous weight to the ominous opening climb, one that truly does feel like we’re ascending into the void, never to return.

And speaking of not returning, Into The Void is also one of Sabbath’s best lopsided songs, structurally speaking. Despite how great the opening riff is, it never comes back, matching the one-sided journey of the title. The solo break towards the end is a standout moment, exemplifying Iommi’s deft handling of blues licks with a strong “less is more” approach.

2. Children Of The Grave (Master of Reality, 1971)

Children Of The Grave is a great example of how well Iommi and Butler play off each other: with no second guitarist, Butler keeps the momentum going for drawn-out chords with relentless gallops and fills. And, the intense, driving palm-muted chugging that kicks the song into gear is iconic in itself.

Here, Iommi’s signature early tone is perhaps the best recorded it ever has been. Given how much fuzz is used in Sabbath-worshipping doom, you’d think that the effect would be all over early Sabbath. But Iommi instead used a Dallas Rangemaster Treble Booster – and on Children Of The Grave you can hear the effect in all of its glory, boosting the upper midrange to fill out power chords with harmonically-rich drive. The upper midrange boost also leaves room for Butler’s bass tone, which has plenty of its own midrange honk.

1. Black Sabbath (Black Sabbath, 1970)

The pattering of rain, a thunderclap, an ominous church bell… and then…

This is it: the seed of all heavy metal. No more complex than an octave leap and a tritone, Black Sabbath’s self-titled song managed to invent a genre with three notes.

Iommi and Butler’s heavy reinterpretation of Holst’s Mars is accompanied by Ozzy’s tortured wails about Satan and Ward’s spacious, powerful fills. The ending riff and solo are an exceptionally good time, too, and often overlooked given the monolithic influence of the opening riff.

The amount of sheer dread captured by this song makes it the undeniable turning point between the heaviest blues rock of the day (later to be defined as “proto-metal”) and the boom of horror-infatuated weirdos picking up the guitar and immediately figuring out the most evil intervals.

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