It was almost inevitable that a conversation with Stone Temple Pilots’ guitarist Dean DeLeo about the 25th anniversary of the band’s eight times-platinum debut, “Core,” would be intense. While songs like “Plush” and “Creep” the album made STP into one of the most commercially successful rock bands of the ‘90s, it also marked the beginning of a career that would be marred by repeated tragedy.

A quarter of a century later, DeLeo still speaks with passion and anger about the band’s charismatic late lead singer, Scott Weiland, who died in 2015 after many years of struggle with substance abuse. After two decades with the band, including several departures and rejoinings, he was fired in 2013 and replaced by the band’s friend and fan — Linkin Park lead singer Chester Bennington, who died earlier this year.

On the day of this interview, DeLeo couldn’t bring himself to say much about Bennington, who committed suicide in July, but he said a lot about Weiland. He also talked about the bond that still exists between himself and brother/bandmate/bassist Robert DeLeo and drummer, as well as plans for future reissues of other STP albums.

As you started to revisit “Core,” what really jumped out at you?
Dean DeLeo: I think the only thing that really jumped out at me was — and how could it not? — Scott. There was just a lot of scratching your head, “Like, what the f— happened, man? You couldn’t get it together? You had to take it there?” That’s what jumps out at me: sadness, anger, puzzlement. I guess that sums up one word, tragic. But, it sums up a time when we were filled with the new, with excitement, with an existence where our dreams could come true. It sounds like a fairy tale, doesn’t it? These are guys that I spent more than half my life with, shoulder to shoulder. I spent more time with Scott, Robert, and Eric than I did with my own wife and children. We knew one other inside and out.

Can you take us through some of the extra material on the reissue?
I think what stands out for me is [a tape] what we unearthed from when we were demoing the record in a little rehearsal room called “Bill’s Place” over on Lankershim in North Hollywood. Boy, it was dingy. Like, on the “Sex Type Thing” demo, all the parts were there. And quite honestly, when we pulled up the track to “Creep” — we had forgotten that middle section was in there — just hearing Scott’s voice and how vibrant he was, it was really sad. I just looked over at Robert and Eric, and we all had tears welling up.

Will there be a 25th anniversary reissue of [the band’s second album] “Purple” in two years?
I actually went through a lot of the stuff for “Purple” and [third album] “Tiny Music” as well — we have a lot of that same kind of stuff sitting around, a lot of the songs kind of evolving from other parts. We have a lot of that stuff and pre-production tapes from the rest of the record as well. There’s a lot of stuff there that’s never been out.

As you go back through this material and it brings up all these memories, are there impulses to play it — and the unreleased material — live?
If we get back on the road — or, when we get back on the road — it’d be nice to tap into some songs that we never played live. For instance, the first time we ever played “Adhesive” live was with Chester — we just brought that song to the surface with him. There’s a lot of material that the band has never played live and Robert, Eric and myself definitely want to explore that.

You guys have been looking for a singer. How’s that going?
It’s going great. We’re working on new material — let’s just say that.

Going back to the early ‘90s, when did you really get the sense that the band was getting big? You went from playing in that little rehearsal room to the Reading Festival in a few months.
I got that sense way, way before the Reading Festival. I got it back when we were still playing clubs. When we were playing around before we got signed, there were some nights we played to 10 people and eight of them were employed by the bar. But when we’d finished recording the album and were still gigging around, we did one show in particular at this club in San Diego called Club 860. It was a bigger club — we had been playing rooms that held 80 to 120 people. I remember pulling up to the venue and seeing the line from the front door going around the block, like there was gonna be about 800 people there that night. And when “Sex Type Thing” was really being played a lot on MTV and across radio, we saw things starting to change. And then, “Plush” came out and the arenas went from being a third full to full. People were there to see the band, people wanted to hear “Plush.” They wanted to see that guy with red hair singing that song. That was a big change, man.

What are the emotions listening to these songs after doing them with Scott and Chester, who are both now gone?
It’s pretty much every emotion. It’s sadness, it’s anger, it’s intense, it’s joy, it’s love. It’s every emotion that the guy who had such a huge flow and such success with this band, and is not here to tell you about it. I hate it. I can’t stand it, man. Like I said earlier, It’s like,  “Really man? You had to take it there?” And that’s what’s tragic about the situation right now because, everything else about it is really, really beautiful. But, heck man. If there’s one thing I could have changed back in the day, it would have been to just ask for Scott to have somewhat of a full heart and a peaceful mind. Scott was an extraordinary human being. Like, anything that guy did, he excelled at. And I know there was a lot of noise in that guy’s head, man. And when he found things that would take down that noise and squelch that fuzz, that’s where he found his peace. And sadly, it killed him.