"People were throwing coins and smashed up cups. It was horrifying!" This is what it's like supporting metal legends Iron Maiden in front of a hostile crowd, according to Atreyu guitarist Dan Jacobs

Even within the wider context of heavy metal's famously guarded fanbases, it is lore that opening for Iron Maiden can be one of the most challenging jobs in the game. While it gives you the opportunity to see the world with metal's most celebrated band and witness one of the genre's greatest live shows first hand for nights on end, it also leaves you exposed to an audience that can be a little on the stubborn side.

From Trivium to Funeral For A Friend, rock music is littered with bands who have supported Maiden and struggled to fully win over their crowds, but few have had a baptism of fire like Orange County metalcore heavyweights Atreyu, who played with the British icons at two Mexico shows in 2009. While it was a dream come true for the band to share the stage with Maiden in such a cool and metal-passionate country, the reality was a little intimidating.

"That was scary as hell," reveals Atreyu bassist Dan Jacobs in a new interview with This Day In Metal (transcribed by Blabbermouth). "People were throwing shit at us and it was horrifying. It was two shows, Monterrey and then Mexico City. Monterrey was in a football stadium - I think it held 30,000 people, sold-out show. We'd never been there before, and at the time we're off the back of our album Lead Sails Paper Anchor and we were pretty successful at the time...It was [Maiden], us and then Carcass, Morbid Angel and then Lauren Harris which is the bass player of Iron Maiden's daughter's band.

"So we get there, and all these bands go on. The show is going great. And it gets to our turn, and we're standing on the side of the stage and our backdrop drops down. And usually the crowd's, like, 'Yay!' and they cheer when that happens. And it was just kind of quiet. We're, like, 'That's weird, okay, but whatever.'

"Our intro starts playing, we start walking out on stage, and we start hearing like 'tink, tink, tink'. And we're, like, 'What the hell is that?' Those people were throwing pesos up on stage or smashed cups and just flicking 'em up on stage or just any random shit."

Jacobs and his bandmates soon realised a truth that had befallen many bands before them and many since: sometimes, Iron Maiden fans just want to see Iron Maiden and nothing else.

"They do not wanna see anybody else other than Iron Maiden or other very, very metal bands," he suggests of the Mexico crowd. "And our band teeters being 'emo' in Mexico, and that did not go over very well. So people were throwing stuff at us the entire set, and it was horrifying. Our bass player got hit in the face with this bullet that was like a keychain that somebody hooked up, hit him on the side of the head, split him open. He was on the cover of the newspaper the next day. It was a whole thing."

Luckily, the next time Atreyu supported Iron Maiden years later, it was in Canada and produced much nicer memories, with Dan describing it as "really inspiring and just a neat experience."

Watch the full interview below. Iron Maiden will be testing plenty more support bands against their crowd on tour this year, with a two-day festival spectacular titled Eddfest taking place at Knebworth Park in the UK in July. Atreyu will release their new album, The End is Not the End, via Spinefarm on April 24.