One sign that things are going pretty well on a package tour is when the headliner invites members of the other acts onstage for a guest spot. That happened Thursday night (May 12) in Denver, when members of Battlecross, Suffocation and Abnormality were invited up by Soulfly onstage to cover a metal classic -- Motorhead's "Ace of Spades."

As you can see in video shot by Resident Rock Star's Amy Hutcheson, it's a pretty packed stage at the Marquis Theater with lots of hair flying, lots of headbanging and just genuine energy portrayed in the performance.

The decision to cover Motorhead at the show should not come as much of a surprise given Max Cavalera's reverence for the band's late leader Lemmy Kilmister. Earlier this year, Cavalera stated that his relationship with Lemmy got off to a rocky start, but did improve over time.

"We got off on the wrong foot. I was really young and Sepultura was opening up for them in Germany. We did a photo shoot and I came with wine and I was throwing it all over him. I was just being a total a–hole. In my head, I thought that was rock ‘n’ roll," Cavalera recalled in an interview with Rock Sverige. “I can see how he looked at me and just saw me as an arrogant a–hole kid being drunk in the middle of the afternoon. Just being a f–king idiot. We got off on the wrong foot and then we went out on their last show all naked and ruined their show and he wanted to kill me afterwards. He told Gloria [Cavalera, Max’s wife and manager], ‘This guy better not come near me.’ And I was like, ‘Ah s–t, I pissed off one of my idols. How did that happen?’ because I loved the guy and his music.”

One of the big turning points came when Max's stepson died in a car accident. He revealed that Lemmy approached him and stated, "By the way, everything is good between us. You're good in my book."

Soulfly are in the home stretch of their current tour with a week left in the run. See their remaining dates here.

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