Halford tells 1290 KOIL Radio: "We were pondering about this the other day in the van driving back from a gig. You know, will there be another great, big rock star giant like Ozzy Osbourne? Will there be another great, big rock star giant like Axl Rose, for example.

"Does that really matter? I don't know. But it's shifted, it's changed. The good news is there's an extraordinary display of talent coming from all different quarters in all different genres of rock and roll."

He adds: "Avenged Sevenfold, Five Finger Death Punch, In This Moment, Royal Blood. There's a ton of bands� Rival Sons� I can keep going and going."

French feels the situation is much more dire, questioning arena and stadium rock's future while suggesting fans better catch ageing acts now before the genre disappears for good.

He tells iradiousa.com: "It's an ageing genre. Name me any rock bands that are 25 and younger who are blowing up the charts. That's the scary part - the replenishment of the genre.