“When it happened, I was bummed out for about two or three days,” he said in the interview, which was part of Jasta’s podcast. The guitarist then went on to explain that he’d “just plain lost it.” “I’m still looking for it to this day,” he said. “I just set it somewhere and…it still might turn up. I’m hoping it will. To try to remember those riffs? I can only remember, like, eight of ’em. So I just chalked it down to maybe it just wasn’t meant to be and I’ll just move forward with it.”

He also addressed the podcast’s listeners: “All you musicians out there who use your phone, make sure it’s backed up. Right?!”

Hammett also offered an update on the group’s new album, calling it “super riffy” and “super heavy.” “It’s a lot similar to [2008’s] Death Magnetic, but different in certain parts. James [Hetfield] is doing a lot of really, really cool melody stuff these days, a lot of vocal layers. ‘Lords of Summer’ is a good example of that, the beginning…. There’s a couple of songs that remind me of something on [1988’s] …And Justice for All, but the album doesn’t sound like …And Justice for All.”

Earlier this month, Hammett estimated that the group was about 30 percent done with the new record. “We have a lot of good songs [but] the songs are ever-changing at this point,” he told Billboard.

The group’s bassist, Robert Trujillo, told Rolling Stone also in April that “what we’re doing sounds heavy” and, with a laugh, that “it’s sounding like Metallica.” Meanwhile, Lars Ulrich exclaimed, “We are fucking in it,” when Rolling Stone asked him about the record’s progress in March. “It’s pretty close,” he said at the time.

“In our world, there’s been a distinct difference between the creative phase and the recording phase,” Ulrich said. “With this project, we’re trying to bridge the two a little more organically and not have there be such a great divide between the processes. We want to see if we can bring some of the creative curiosity, the impulsive stuff that happens when you’re first playing a song into the studio.”