Aerosmith star Joe Perry is adamant he was deadly serious about replacing Steven Tyler when the frontman shocked his bandmates and fans by announcing plans to take time off last year.

Perry admits he knew his songwriting partner wouldn't be gone for long, but he was committed to finding a stand-in so the band could honour a string of 2010 shows - just in case.

And he tells Guitar World magazine he really would have hit the road with another singer if Tyler's hiatus had continued.

Perry says, "I was just looking at it as working with somebody and jamming, as a temporary thing.

"People were flipping out, like, 'It's not going to be Aerosmith.' Well, no s**t. You don't have to tell me that. But who knows what could have come of it?

"I knew he (Tyler) would come back. I just didn't know when. But I was glad it was sooner rather than later."

Tyler returned to front the band after a rehab stint and now admits he and Perry have patched up their differences.

He explains, "It was a real trying time for me. We (Perry and I) didn't speak to each other for a while... and Joe just decided to look for another singer. I don't know what he was thinking, but we've since made amends to each other and, more importantly, the band's playing better."

Aerosmith kicked off the North American leg of their world tour on Friday night with a show in Oakland, California.