There have been quite a few successful supergroups in rock, one of which was Audioslave, a fusion of Rage Against the Machine and Soundgarden vocalist Chris Cornell. But how did the members of Rage decide on Cornell to be their new frontman at the time?

Audioslave formed in 2001, shortly after Zack de la Rocha left Rage Against the Machine. Soundgarden had broken up a few years prior, and Cornell already had a solo album under his belt, 1999's Euphoria Morning. Rage Against the Machine and Soundgarden both found great success during the 1990s, but didn't seem to cross paths much aside from festivals such as Lollapalooza.

Eventually, though, Tom Morello, Brad Wilk and Tim Commerford of Rage and Cornell joined forces. They released three albums during their time as a group — Audioslave (2002), Out of Exile (2005) and Revelations (2006) — before calling it quits in early 2007.

So, how did Cornell even become the singer of Audioslave in the first place?

How Did Chris Cornell Become the Singer of Audioslave?

De la Rocha left Rage Against the Machine in 2000 after releasing four albums with the group. He said in a statement [via Far Out Magazine], "I feel that it is now necessary to leave Rage, because our decision making process has completely failed. It is no longer meeting the aspirations of all four of us collectively, as a band, and from my perspective has undermined our artistic and political ideal.

“I am extremely proud of our work, both as activists and musicians, as well as indebted and grateful to every person who has expressed solidarity and shared this incredible experience with us.”

Morello, Wilk and Commerford wanted to continue making music together, though, so they met with producer Rick Rubin and brainstormed. According to an interview with Howard Stern, Morello recalled that they listened to Soundgarden's 1991 album Badmotorfinger a lot during that time, and as suggested by Rubin, they decided to meet with Cornell.

"I think that Soundgarden, and Chris Cornell in particular, helped redeem hard music," Morello said. "Chris was smart, and you could tell. And he was poetic, and he had this kind of dark, poetry that connected on a level that felt... but he also unapologetically embraced the big riff-rock."

As reported by MTV, Cornell had been offered to sing for a few other bands after he left Soundgarden, but only considered auditioning for this new band because he received a call from Rubin. And at their first rehearsal, he was extremely impressed by their musicianship.

"I just thought, 'I am lucky. I get to be the singer in this band if I get up there and I am good.' So I decided to be good," Cornell said, with Morello adding, "He stepped to the microphone and sang the song and I couldn't believe it. It didn't just sound good. It didn't sound great. It sounded transcendent. And... when there is an irreplaceable chemistry from the first moment, you can't deny it."

How Did Tom Morello Have to Adjust His Guitar-Playing to Fit Chris Cornell's Singing?

Despite the chemistry the band felt with Cornell, they certainly had to adjust their playing to match his vocal style — particularly Morello.

READ MORE: 10 Unbelievable Supergroups That Actually Almost Happened

"[Cornell's] ability to craft melody out of the ether... He would effortlessly create something that was either beautiful or terrifying," the guitarist told Stern in the aforementioned interview. "His strengths were with melody, and it really challenged and pushed Tim and Brad and I... With Chris, in order to allow him to shine, there had to be this kind of harmonic counterpoint. That song 'Like a Stone,' it's a few simple power chords, but it allows Chris' beautiful voice to soar."

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