Kim Thayil acknowledges that he "wasn't sure" if he was ready to get out and play in public again when Wayne Kramer called him earlier this year to be part of MC50, his new band celebrating the 50th anniversary of the recording of the MC5's debut album. But as the group prepares to start a North American tour on Sept. 5 in Fort Lauderdale, Fla., the Soundgarden guitarist says it's been just what the proverbial doctor ordered.

"(Kramer) asked if I wanted to play, and my jaw dropped," Thayil, who had been largely out of sight since Soundgarden frontman Chris Cornell died by suicide last May in Detroit, tells Billboard. "I thought two things -- 'Am I ready to come out of the fetal position?' and then 'How could I be any more ready than this opportunity to play with what I consider to be my favorite band.'

"So I made myself ready. It was like, 'Fix your head. This is The One!' When I mentioned it to friends of mine they didn't hesitate; They said, 'Omigod, jeez, this is your dream. You should do this!' The timing was pretty good, I think. I was allowing myself to be ready."

Thayil has been an MC5 fan since he was a teenager and began reading references to the MC5 and the 1969 Kick Out the Jams album in periodicals and interviews with other artists he liked. "At some point I started getting into some heavier music than I was hearing on AM radio and kinda learned to switch the dial from AM to FM and find significantly heavier and trippier music than what I was hearing before, and it was right up my alley," Thayil recalls. "I think I really connected with the MC5 because there was so much to that music. Obviously a band like the MC5 has the influence and appeal across a number of genres -- the obvious ones like acid rock and heavy metal and, later, punk rock, but I would draw a line from the song 'Shakin' Street' to (Bruce) Springsteen's work. And there was the free jazz (the MC5) drew from. So there was a lot there."

The all-star MC50 played a few dates in Europe earlier in the summer, during which Thayil reunited with Soundgarden drummer Matt Cameron. The group -- which also includes Zen Guerilla's Marcus Durant on vocals, Faith No More bassist Billy Gould, Fugazi's Brendan Canty on drums -- wraps the North American tour during late October with two shows in the MC5's home turf of Detroit (where the MC5 recorded Kick Out The Jams live during Halloween weekend of 1968), then returns to Europe during November. MC5 drummer Dennis Thompson, the only other surviving member of the band, may participate in some shows, but on an ad hoc basis.

For Thayil, the immersion has been not only a welcome return to music but a chance to learn even more about his favorite band. "It kind of appeals to the Soundgarden aesthetic," Thayil explains. "There's a combination of those same elements -- a progressive element but also a heavy rock thing and a loose, wild thing -- that I see in MC5. Some of the songs have some really curious, interesting parts, little time changes that can throw the drummers for a loop. Learning as Wayne showed us, there's a lot of stuff that wasn't as readily obvious as you would think by listening to the records, and that was kind of a surprise. And it was cool."

As for the future of MC50, Thayil says he's "getting that vibe" that the group could become a going concern and even make its own music. "I think everyone enjoys each other's company and makes each other laugh and has a similar sort of social and cultural sense about them," he notes. "It does tend to be an open-minded, progressive, forward-thinking group, which I think is probably appropriate for the MC5."

Thayil says that prior to getting the MC50 call he'd been "up and down, in and out" in the wake of Cornell's death. "Everything has improved day by day," he says. "Obviously there's still emotional shadows and ghosts. Like anything else it's something that improves with time." He says he, Cameron and bassist Ben Shepherd "still talk to each other frequently and text and call and check in on each other and see how we’re doing. I imagine we will do more things in the future, one of which will be Matt sitting in on a few more MC50 shows. I'm sure I'll do stuff with Ben as well." Thayil does, however, dismiss notions that anything was visibly amiss with Cornell during Soundgarden's May 17, 2017 concert at the Fillmore Detroit prior to his suicide.

"I thought the show was good," Thayil says. "I remember Chris had just gotten in (to town) and was a little tired and his voice was a little rough, but by about the fourth or fifth song it kicked in and then it was just, like, super amazing -- beautiful, clear and strong and, I thought, particularly emotive." Thayil adds that a moment of the show when Cornell was absent from the stage for a protracted period when the guitar he'd be playing was out of tune and a backup wasn't immediately ready. "He had to leave the stage, I remember, and he just kind of poked his head around and said, 'Go ahead, start without me,' at which point Ben started jamming on something and we all fell in until Chris was ready," Thayil says.

"People speculate, and they get causality in reverse," he adds. "I guess it's natural to try to fill in the blanks to explain a particular mystery," he adds. "I think it's natural to say that, 'We know something terrible happened, so we know there must have been some sort of problem. Let’s see what that problem might be. Well, come to think of it, the show was kind of messy....'"

Soundgarden has been in the midst of archival projects in recent years, with expanded editions of albums such as Badmotorfinger and Superunknown and others. No future releases have been planned yet, and Thayil says he, Cameron and Shepherd are still grappling with how they want to proceed.

"We often reference rock history and we've often commented on what other bands in similar situations have done," Thayil says, "not as a plan or anything but just commenting on how bands have handled situations like this and what bands seem to have been graceful and dignified in how they manage their future musical endeavors and how some maybe were clumsy and callous. We think about those things. We try not to go too deep into these conversations, but stuff comes up after a few beers."