Over the course of eight albums, the Canadian twins Tegan and Sara have repeatedly reinvented themselves, seguing from strummy Ani DiFranco-isms to spiky-guitar new wave to indie angularity to electronic pop. But of all those transformations, it’s the Quin sisters’ shift to collaborative songwriting that might have been most startling. Before 2013’s “Heartthrob,” Tegan and Sara songs were either Tegan songs or Sara songs, each with their own identifiable sensibilities.
“I tend to be the one that doesn’t write the pop songs,” Sara Quin says on the phone from Nashville. “I feel like I’m often the one that writes the deep cuts of the album. I’ve not always been able to distill a more complex story or a lyric into something that is also really catchy. I think that Tegan does that super well. I’m not always good at that.”
The recent foray into writing together has helped the duo (whose Halloween concert at House of Blues will also be livestreamed on lntv.com) stretch on their effervescent new album, “Love You to Death.” “I look for ways to still have those kinds of idiosyncrasies that I know were interesting about what I was doing when I was younger,” Sara says, “but I’ve taken cues from Tegan’s writing in terms of arrangements, and I’ve decided, ‘OK, I want to be able to marry those two things.’ ”
Quin spoke to the Globe about the parallels between her songwriting and her personal life, how her sister gets all the good songs to play live, and why Tegan and Sara are not U2.
Q. Every couple of albums, you seem to go through another substantial stylistic shift. What’s prompted that?
A. I think because we see ourselves as songwriters, I don’t know that we necessarily ever strongly identified with one genre of music. There are certain bands that you want to sound [a certain way]. Like, U2 needs to sound like U2. Radiohead needs to sound like Radiohead. I think the thing that makes us sound like us is our voices.
Q. “Boyfriend” feels like one of the most emotionally and situationally complex pure pop songs since Robyn’s “Call Your Girlfriend.” The narrator is being pulled in a lot of different directions at once. How do you distill that down to a pop song that lasts less than three minutes?
A. I think that we all end up doing things that don’t always feel like they’re representative of how we are in the rest of our life. I don’t generally think of myself as being the “boyfriend” in the rest of my life. I feel like that’s a role that I’ve sometimes played in romantic relationships. And I don’t mean sexually, I mean that I don’t talk about my feelings, or I put myself in a position where I wait for someone else to leave me. I feel like I’ve at times waited to be pursued by the girl, or I take on these sort of dumb stereotypes of what guys do in relationships.
And I find that really interesting, especially right now in a world where we’re talking a lot about those binaries and those intersectional identities for not just for gay people but for straight people, too. But how do you put all of that into a goofy pop song? [laughs] It’s hard. So it took some finessing.
Q. You had talked about the fact that Tegan tends to write more of the pop songs and that’s something that you have to struggle to do, and then you’ve just described the way you are in relationships almost exactly in the same way.
A. I don’t know if it’s as much about being emotional or not, but it is about how much you reveal. Tegan has a stripped-down ability with her lyrics. A song like “Nineteen” or “Call It Off,” some of the Tegan favorites that people get amped about at shows, they’re so bare. And I don’t think being simple is a bad thing, but I don’t necessarily have that ability when I’m writing songs. I think there’s a protective layer or a complexity to what I’m trying to say sometimes in music that makes it harder to connect to. I definitely think that that’s my personality.
Q. By the time of [2007’s] “The Con,” I got to be pretty good at identifying which of you wrote any given Tegan and Sara song without looking at the credits. Tegan tended to write the more pop-minded and -structured songs, where yours tended to be a little more arty and modular.
A. It’s funny, I think that those songs from our past, the ones that have less-traditional arrangements or how you described them, being more modular . . . I love that material, but I find it just so frustrating to perform. “Walking With a Ghost” has a funny buoyancy that allows it to be interesting even though it’s really just two parts repeated. But most of the other songs that I [wrote] using a similar technique, creating these nonlinear songs, I desire playing them so little. A decade has stretched by without me ever wanting to play a song like “Knife Going In.”
There’s something about listening to them that has a pleasure to it, but to actually perform them, you never lift off. You never get any of that climax that is so interesting and needed in a concert. We’ve reworked some of those other songs so that they have that. But the original recordings of them are sort of stressful to me, because they can only really exist on a recording.
TEGAN AND SARA
‘I tend to be the one that doesn’t write the pop songs. . . . I think that Tegan does that super well.’
With Torres. At the House of Blues. Oct. 31 at 7 p.m. Tickets: $35-135. 800-653-5000, www.livenation.comInterview has been edited and condensed. Marc Hirsh can be reached at firstname.lastname@example.org or on Twitter @spacecitymarc.