Slipknot's Joey Jordison was left with bleeding hands every day when they were making 2001 album 'Iowa'.
The group's DJ Sid Wilson said the drummer was forced to bandage his hands up due to the "brutal" recording process the group went through to get the record - which was re-released last month - just right.
He said: "All that's important is the music and what you're trying to get across to people. It's brutal. Joey's hands would be bleeding at the end of the day. Every day, his hands would be bandaged up from how hard he was pushing and trying to open the envelope even bigger."
The 33-year-old musician described the way the band's late bassist Paul Gray - who was found dead in a hotel room last year aged 38 - would be "unreal" at taking a song on 'Iowa' to pieces and making it better, pushing the band to create the best possible album they could.
He added in an interview with ArtsDirect.com: "That was a really cool thing with Paul. He always brought that to the table big time. We'd be like, 'This is it right here,' and he'd say, 'No, there's something missing. That could be done a different way. There's another angle.'
"He would play the part forward, backward, upside down, and in reverse. He'd change, add, and take away and do every solitary thing you can think of to alter it so he knew every single possibility of executing a part.
"His modem was open to so many different planets. I'm not really sure how many transmissions he was getting, but the way he would dissect a piece of music was unreal.
"His doing kept everyone's minds open. It helped us stay true to what we felt was the real deal and not everybody else's opinion of it. We were giving truly what was part of ourselves."