Tony Iommi on future collaborations with Ozzy Osbourne, the best Black Sabbath riffs and which was Eddie Van Halen's favourite

Tony Iommi knows a good riff when he hears one. But then, considering he helped create heavy metal's iconic sound with Black Sabbath , that should go without saying. But in a new interview with Loudwire Nights , the guitarist was asked to name a riff he instantly knew was special - and naturally it posed a problem.

"Well, without sounding big-headed, [we'd got] a few!" he says with a laugh. "When we'd first done the Black Sabbath riff, straight away I knew — it just had this vibe and a feeling and it was something so different in them days that you'd never heard that sort of thing before."

"I don't know how it all happened," he admitted. "It'd just sort of come out. And that was the benchmark for that album. Once we'd done Wicked World and Black Sabbath , then the rest of them flowed along. The same with Sabbath Bloody Sabbath ."

Iommi also revealed fellow legendary guitarist was a big fan of Masters Of Reality track Into The Void .

"That was a riff that I really liked, and that was Eddie Van Halen's favorite, to be honest, Into The Void," he says. "[Eddie would] always say, 'Oh, play Into The Void . So it was great to hear that. So there's a few that sort of — for me, Iron Man . Oh, there's a lot that really meant something. Well, they've all meant something, but they're the ones that sort of stood out initially."

As part of the interview, Iommi also spoke to host Chuck Armstrong about the many different line-ups of Black Sabbath over the years, including the Tony Martin-fronted era of the band. Black Sabbath recently announced a long-awaited reissue of the four albums Martin recorded with the band in the boxset Anno Domini .

But while fans might be excited that the Martin era finally getting its time in the sun, chatter lately has surrounded comments from the original members of Sabbath that they still hope to do "one last gig" with original drummer Bill Ward, who was not part of the band's 2012 reunion or farewell tour.

Chuck asks if Tony will likely collaborate with Ozzy Osbourne on a song again - in Black Sabbath, Iommi or otherwise. "Well, we did," Tony replies. "On his last album [ Patient Number 9 ], we've done two tracks together. He asked if I'd got anything and I sent some stuff over, he liked it and we went ahead with it. So yeah, we've done that."

"But who knows?" he continues. "I look at everything nowadays, I don't say 'oh I'm not going to do that'. I have to think it over and anything that comes in the future, I always give it a thought."