McBride was already familiar to the Purps from playing with Don Airey’s solo band, which then also backed Ian Gillan on a rock-meets-classical tour. He was originally going to be just a fill in for Morse on their previous tour. But when Morse needed to leave the group permanently to care for his ailing wife, McBride was the logical choice for replacement. No one else was even considered.

“I hate auditions. They’re a real drag!” Glover laughs.

Bob Ezrin’s return to the producer’s chair was similarly almost a foregone conclusion. “He’s energetic, dynamic, and a good musician and songwriter himself. And he works very quickly,” Glover says.

“But more than that, he recognized things in us that we didn’t ourselves. When he first saw us in Toronto 12 years ago, what struck him was the musicality and the spontaneity of Deep Purple. We don’t learn solos to play them, they’re fresh every night. And that’s what got him.”

For comparison, Glover says the band’s 1987 effort The House of Blue Light, which the band produced themselves, took six months to record. For =1, he estimates that they laid down the basic backing tracks for 15 songs in 11 days.

“There’s no such thing as ‘Take 49.’ It’s usually two takes at the most, and if it’s more than that, you lose something,” he says.

Topics of the tunes include familiar Purple territory of love, lust, scheming women, and the occasional orgy. But its first two singles address more contemporary concerns. There’s the blabbing, boring, and forceful opinion spouter of “Portable Door,” and the romantic seeker whose online dating profile photos don’t quite match up the current reality in “Pictures of You.”

“When you write lyrics, the world seeps in. You can’t ignore it. And the world around is pretty dire at the moment. But then again maybe it’s always been dire,” Glover offers.

“Conversations, memories, newspapers, we [use] it all But no one person in the band speaks for the band. That wouldn’t work for us, it would probably break us up. We stay away from politics or preaching, unless it’s an overall observation.”

Something that undoubtedly goes a long way to keeping the band together is that all five members—along with Ezrin—share writing credit on all 13 tracks. And there’s a reason.

“It takes the five of us to write everything. Nobody comes to a Purple session with a completed song. When I joined Purple, they were mostly known for doing covers. Then we started writing our own. It’s a whole feel. The way the drums are played are as much part of the writing as a riff or a word. And we always decided to share credits,” he says.

“When Ian [Gillan] and I left the band in ’73 and [David] Coverdale and [Glenn] Hughes came in, Ritchie changed that. He said ‘No, he who writes gets.’ Because in his mind, he was writing most of the stuff. Now, it’s a guitar-based band, so a lot of the stuff came from him. But not all of it.”

He mentions that even Blackmore’s opening riff to “Smoke on the Water”—one of the most famous openings to one of Classic Rock’s biggest song—is just part of its entire makeup.

After Blackmore left the reunited and best-known “Mark II” lineup in 1993, Glover said they decided to go back to more collaborative credits (for those keeping count, the current lineup is “Mark IX”).

He adds that it takes away a lot of jealousy and unease about choosing which tracks (and thus, the writer’s royalties) about which songs are picked to include. Something he feels goes against the very nature of creativity.

Glover admits to going through a rough patch after that contentious ’73 departure. “I was pretty depressed, blown apart actually. This wonderful dream I had just lived for four years of going from nothing to owning the world suddenly stopped. And it was difficult to take,” he says.

But his spirits—and professional resume—were buoyed by the sudden success of a little-known Scottish hard rock band whose third record he produced: Nazareth.

Glover stuck mostly to producing for several years until joining Blackmore’s “other” band, Rainbow. Then their paths led back to Deep Purple.

Finally, audiences across the world will get to hear both material from =1 and songs from across their 56-year history this summer as the band embarks on a world tour. It will bring them to Houston at the Woodlands Pavilion on August 17, with Prog-rock kings Yes opening.

With some creative math, the current tour marks “50 Years of ‘Smoke on the Water.’” And the album that birthed it, 1972’s Machine Head, was recently reissued in a Super Deluxe Edition.

Amazingly, its tale about a mobile recording unit, a floating Swiss casino burnt to the ground with a flare, and a cameo from Frank Zappa and the Mothers of Invention is a true story. More amazing was that this epochal piece of rock and roll history was never meant to be issued as a single. And its success was a shock to the band itself.