Keeping the Sabbath holy

In a feat of rare alchemy – one often repeated throughout the band's career – Black Sabbath turned four measures and a mere six notes into one of the most recognizable phrases in rock music: the main riff of "Iron Man," from 1971's Paranoid.

Hard rock, soulful swagger: Friday night headliners Clutch follow the riff where it leads.

That most of Black Sabbath's (and many of its hard-rock contemporaries) songs were built from such foundational riffs is hardly without precedent. It's a structural element hard rock and heavy metal share with most other forms of popular music, including jazz and the blues from which rock 'n' roll was derived.

But the chemistry shared between Ozzy Osbourne, Geezer Butler, Bill Ward and Tony Iommi gave life not just to a memorable melodic hook; not just a riff, but a riff, and a legacy.

This weekend, the Planet Caravan Festival – named for one of the more hazy, psychedelic cuts from Paranoid – celebrates that legacy. For two nights, 20 bands, each with their own interpretation of Sabbath-style riffs, will converge on Asheville, putting fans back in touch with the influence of Black Sabbath, the power of deft melodic phrasing and the epic stuff that springs from both.

"We definitely share a common musical interest with a lot of the bands that are on the bill – if not all of them," says Dan Maines, bassist for Friday night headliners Clutch. His band warps riff-based hard rock into a soulful swagger, led by lead singer Neil Fallon and his inscrutable tenor. Saturday's marquee, Pentagram – a band Maines claims as a major influence on Clutch's early days – stays mostly true to its '70s origins, wielding thick riffs that still echo in Metallica's and Sleep's early recordings.

Veteran guitar hero Scott "Wino" Weinrich, formerly of influential bands St. Vitus and The Obsessed, leads his eponymous band on Friday evening, following sets from Eastern N.C. sludge-slingers Sourvein and the reggae-inflected Lionize. Younger and more adventurous bands, like Georgia's Kylesa and New York's Tombs, bring punk and black metal influences to the table as well.

Saturday brings back-to-back sets from doom outfits Salome (Virginia) and YOB (Oregon), both of which drop their riffs lower and slower, drawing resonant tones across epic-length songs. YOB tends to twist and manipulate the riffs' direction to create dynamics over time – "like a mix between death metal and classical movements, where there are a lot of riffs and there are a lot of tempo changes," says YOB leader Mike Scheidt.

But no matter how the music evolves, there is always that common ancestor. "You gotta remember, I saw Sabbath on the Paranoid Tour in '72," Weinrich says. "That's the kind of stuff I was born and raised on."

Phillip Cope, one of Kylesa's two singer/guitarists adds, "If there weren't Sabbath, there wouldn't be Kylesa, that's for sure."

And there's the omnipresent cornerstone of hard rock songwriting: the riff. The riff is a first impression, a foundation which can be extrapolated and expanded, taking the listener in unexpected directions. Or it can run on repeat to induce a sort of hypnotic euphoria. The riff, says Scheidt is only the first step. "The song is as important or more important than the riff," he says. "It has an initial impact on the listener, but if the song doesn't live up to it, then so what? Obviously Black Sabbath had a lot of great riffs, but they had great songs and that's why people remember them."

The Oregon-based doom metal band YOB.

But in the gray area in which a riff transforms into a song, there is something mystical and hard to pin down. Even Weinrich, with his years of experience, says the creation is something ephemeral. "Something will spur my interest – something in life," he says, explaining his songwriting process. "I'll be thinking of that and I'll come up with a concept, like a title. Once I have the title, I'll come up with a riff that I really like, and I'll know right away when the riff and the concept lines up."

Knowing when a riff works is instinctual, something that is confirmed when the band turns up the volume and, as Cope puts it, "we start bangin' our heads." The effect is much clearer than the cause.

"It's amazingly easy to write a riff that is easy to forget, or easy to lose interest in," says Clutch's Maines. "Something that you can sit on for a while and maintain interest in is a sign of a good riff." For Clutch, a new riff in practice usually reveals itself quickly as either potentially successful or destined for the trash heap. "We usually fall into a free-form jam and just follow it wherever it leads us, and just wait for that moment where it becomes something tangible."     

That entity, the thing the riff grows into, is responsible for some 30 years of heavy metal: a genre that has thrived despite critical and popular derision to become one of popular music's most varied, vibrant and resilient subcultures.

This of course, isn't to say that all metal is forged equally. "There's lots of music that's just chords and notes," says YOB's Scheidt. "But sometimes people will tap into those chords and notes and breathe life into them … If you have a great idea, it has a life of its own."

Kylesa's Cope echoes Scheidt. "Sometimes, when certain people get together, shit just happens, and it happens really good. I know when I hear it, that it was a damn good thing that it happened."

Bryan Reed is assistant editor of Shuffle Magazine and a contributor to publications including Blurt Magazine and Tiny Mix Tapes.

who: Clutch, Pentagram, Wino, YOB, Kylesa, Salome, Orange Wizard, more
what: Planet Caravan heavy music festival
where: The Orange Peel (5 p.m. $79.50 for both days. Ages 16 and older. www.theorangepeel.net and www.planetcaravan.com)
when: Friday, Sept. 19 and Saturday, Sept. 20