Picture this: you're in a bar (remember those?) and a song comes on that you haven't heard before. The singer of the band sounds familiar, but you can't quite place them. "I know that guy..." you'll agonise to yourself until the music comes to a close.
But then, another song comes on straight after, and all it takes is one word from this new singer for you to go, "Now THIS one I know!"
There's a reason the lead singer of a rock or metal band is known as the frontperson. They're the one strutting about centre stage; the one in the outlandish leather gear; the only member whose name the entire audience is guaranteed to know. Their energy embodies the spirit of the band - and with that unique responsibility comes an equally unique set of pipes.
These are the vocalists whose voices you'd recognise anywhere. From the screechiest falsetto sirens to the whiskey-soaked rusty-nails raspers, never has there been another battle cry that bears a lick of resemblance to those of this list's rock 'n' roll icons.
And whether you're a fan of them or not, you know their hearty call from a mile away. For it's truly one of a kind.
15. Dave Mustaine
A polarising entry right off the bat, Megadeth is very much the marmite of '80s thrash metal. Naysayers will claim that the band rose to fame by riding the coattails of their singer's previous band, Metallica, while others maintain that, unlike the latter, this group managed to stick to their roots over the years and, as a result, hone it to perfection.
But I digress, as Megadeth are, indeed, one of the Big Four of bay area thrash, and frontman Dave Mustaine is one of metal's most celebrated names. That, and what an unusual singing voice he has.
Looking at him, you wouldn't expect such a high-pitched, nasally timbre to come out of a six-foot-one, no-nonsense California dude. The tone cuts right through the chugging thrash guitar underneath, creating a sound that serves as kind of a halfway point between the voices of James Hetfield and Joey Belladonna (Metallica and Anthrax, respectively).
It's not for everyone, I'm sure, but there's no denying that his singing is instantly recognisable - even among the hundreds of other nasal rock screechers out there.