THE NEW THERMALS album is bookended by the songs "I'm Gonna Change Your Life" and "You Changed My Life," and over the course of Personal Life, braggadocio turns into self-loathing, trust evolves into doubt, romantic ecstasy lapses into tortured obsession. In other words, it charts the course of a modern-day relationship in harrowing, unflinching terms—but it does so with crunchy, energetic pop melodies that never for a second sound overburdened with woe. It's the Thermals' specialty: songs that knife you in the gut, but in turn elevate and elate the listener. Personal Life is their most cathartic yet, dealing with the interior rather than raging at the world outside.

In fact, coming after the angry religious polemic of 2006's The Body, the Blood, the Machine and 2009's death-obsessed Now We Can See, the new record initially seems a bit lighter. But when I ask guitarist/vocalist Hutch Harris if it's a happier record than its predecessors, he exhales sharply. "I don't think so," he says. "Maybe. It's more just about down-to-earth stuff; it's just less about chaos and religion and politics and death and water and drowning and shit like that." His two bandmates, bassist Kathy Foster and drummer Westin Glass, start laughing. "Well, seriously, but I mean it is!"

"So in that sense, it's lighter," says Foster.

"It's called Personal Life, but it's about relationships," Harris continues. "Mostly, it's about unhealthy relationships, or just about relationships going bad."

"The dark places," adds Foster.

"Yeah. The dark side," Harris says. "The lyrics are way more simple than the past couple records—unconsciously. They're just very simple, almost kind of remedial. I was thinking of diary stuff when you're 17 or 18. I've been listening to Siamese Dream nonstop lately; I love that record and I go back to it every once in a while. I love it, but a lot of those lyrics are, god, they're so just like what a 16-year-old girl would write in her journal. But a lot of that is why people love that record so much.

"And then musically, the last two records were just Kathy and me," he continues. "They were projects where we were never playing the songs fully; it was just Kathy on the drums and I was on guitar and then we'd layer stuff on a four-track or an eight-track. It wasn't until the songs were finished in the studio that we actually heard what they sounded like. But since Westin started playing with us, we actually started writing—the three of us—all together. There were no guitar overdubs—there's, like, one vocal overdub on the record. What we were playing every day in our space and what we play at shows now—that's exactly what the record sounds like, for the most part. So that was cool; that was just a way old-school thing to do. The record sounds like the band going in one room and playing and someone recording it."

That someone is producer Chris Walla, who recorded their 2004 record Fuckin' A, which—perhaps not so coincidentally—is the last time the Thermals recorded as a three-piece. Hewing close to a live sound and not relying on overdubs was of utmost importance this time around. Foster says, "I was really adamant about it: 'We're playing every single one of these songs live!' There were a couple times where Hutch was like, 'Maybe keyboard...?' And I was like, 'No!' I really wanted to play all the songs live. And I think that's just kind of how we write songs when it's a full band. When you're writing a song that way, you're just conscious of the dynamic, but it's easier to be conscious of it as a three-piece rather than a two-piece, where you're trying to hear the third part. We're playing it live together, and if something sounds like it's missing, then we'll adjust live, as we're writing the song."

If it sounds like the Thermals are having fun playing, the songwriting suggests a darker outlook. With each listen, the seeming simplicity of Personal Life retreats, revealing a complex and dark emotional undercurrent, resulting in the finest breakup album since Frightened Rabbit's The Midnight Organ Fight. No other album has conveyed a complete inner collapse while maintaining an outward appearance of confidence. Take the desultory "Alone, a Fool," in which a strumming guitar and Harris' voice waver between hope and despair, punctured by a crack of the snare drum. Or the stately gait of "A Reflection," which describes the sheer longing of a romantic union, then dissolves into feedback and squalor, much like a relationship that has the rug pulled out from under it. It's followed by "You Changed My Life," a resigned but optimistic conclusion that deals with loss of love with remarkable emotional maturity.

Lyrics aside, much of the record's strength comes from the watertight interplay between the different musicians, and I ask Glass if he still feels like the new guy. "It didn't feel that way even from the beginning," the drummer responds. "Hutch and Kathy made me feel like such a part of the band from the very beginning. I've played in so many bands over the years and this has been the first time that every single thing I wished the band I was in would be, this band is it and more. Not that any of the bands I've played in before weren't awesome; they were. But this is the band I've been wishing for my whole life. These guys have really made me feel like an equal partner. And musically, I feel so comfortable playing with these guys. The way Kathy writes drum parts is like the same way that I would write drum parts. When I was learning all the older songs, it felt so natural to me because the fill that Kathy would do, if I was writing a drum part to that song I would do a very similar fill in the same place. It feels very comfortable."

It's obvious that the members of the band genuinely like each other's company. "That's always been really important to both me and Hutch," says Foster, "because we've been playing together since 1997. And just my whole history of playing music—I've always played with people I'm really good friends with. So that's always been one of the most important factors of playing music for me, to get along and to have fun and be friends."

"You always hear about bands that don't get along, that don't even like each other," adds Harris. "I couldn't do that. The standard that we have now, the three of us—if it wasn't this, I couldn't do it. I wouldn't want to do it if it was anything less than this. The way we have it is so positive and so fun."