Skating Polly’s music simmers with the kind of gritty, hard-won confidence that comes from having played since an early age.

Since starting their band in 2009, when they were just nine and 14 years old, the Tacoma, Washington-based stepsisters Kelli Mayo and Peyton Bighorse have recorded four albums, toured with Kate Nash and Babes in Toyland, and won the endorsement of Exene Cervenka, of the seminal punk group X.

The duo’s trademark “ugly pop” layers bratty vocals over grungy, thrashing chords, and twee melodies. In 2011, Skating Polly developed a larger following with the release of their third album Fuzz Steilacoom, which showed off the Oklahoma natives’ songwriting chops. Its highly-anticipated follow-up, the searingly raw The Big Fit, comes out on March 25th through Chap Stereo via Burnside Distribution (you can preorder the album here).

For a band that goes record shopping with Kliph Scurlock (the former drummer of the Flaming Lips, who they refer to as their “satan father”) and trades texts with Veruca Salt, Bighorse and Mayo, they are delightfully unaffected and down-to-earth, fan-girling over Neutral Milk Hotel and tipping me off to the best place to buy knockoff Samoas (Big Lots, in case you were wondering). She Shreds sat down with them to discuss coping with jealousy and pushing out of their comfort zone on The Big Fit (which you can stream here today!).

Kelli, how did you get into playing the basitar (a guitar-bass hybrid)?

Kelli Mayo: I grew up around a lot of instruments, and my dad was always trying to teach me how to play guitar. But I was nine. I didn’t really like guitar, I liked bass [because] guitar hurt my fingers. I wanted to play bass, but my arms couldn’t reach on a full-scale bass. My dad heard about this instrument called the basitar, created by the Presidents of the United States of America. It was a guitar body with two bass strings, tuned to C# and G#. You just play them both on the same fret, and it makes a chord. We slowly changed that into putting it on a mini-scale bass, and I added an E string, and now I have this completely Kelli-customized basitar.

You two have been working together from such a young age. Is it difficult letting other people in on that partnership?

Peyton Bighorse: It can be tough, but I feel like the people who worked with us on this album, understood what we wanted to do more than we understood it. We mixed in the same room as [engineer] Jim Vollentine for a few songs, and we would just be sitting there while he was working his magic, and we would be like, “Whoa! How is he doing this?” He would just get it and be like, “What do you guys think? This is the rough mix!” And we would be like, “This is the rough mix?!”

You’ve said that you feel you’re sharing a side of yourselves you’ve never revealed before on this album. What makes The Big Fit more vulnerable than work you’ve done in the past?

Mayo: Personally, I’m not trying to hide my lyrics as much behind things. On [our first album] Lost Wonderfuls, a lot of the songs would be stories I just made up in my head. It wasn’t really until later that I had any kind of personal connection with it. Then I just slowly started writing about things, but I would really want to hide behind layers and layers. On this album, I’m more open about it. Friends will hear a song I’ve written, and they’re like, “Oh, I remember that.”

Also, on every song, we’ve pushed ourselves musically. We would try to do things we could barely play at first. We just pushed ourselves to the extreme. We’d learn a trick on an instrument, and then we’d be like, “Okay, let’s try to write a song with this trick that we can barely do!”

You recently did a songwriting session with Veruca Salt in L.A. What was that like?

Bighorse: I feel like every time we do something like that, like working with Veruca Salt, or going on tour with Babes in Toyland or Kate Nash, we always come out better musicians. Going in, I was really nervous because I wasn’t very confident in my drums. I was just like, “well, all I can do is this 4/4 classic beat.” [But] it was such a comfortable working space that I was able to let loose, and it’s really helped me because I feel like I can do drums better whenever we’re writing our own songs now.

Mayo: Yeah, Peyton just kind of went for it, and she wrote this drum part that was insane and weird and kind of off-kilter. It’s always more comfortable to do something that you’re used to, but it’s usually not as successful or interesting or cool!

You’ve gotten to collaborate and tour with so many amazing artists. Do you have a musical hero you’d love to work with but haven’t gotten the chance to yet?

Mayo: So many! I would love to work with Jon Brion. I watched the Elliott Smith documentary and wanted to work with him even more. He did the original mixes of Extraordinary Machine, he worked with Kanye West and Spoon. Also John Congleton, who worked with St. Vincent on her self-titled album. He’s a really great producer.

Bighorse: Obviously I would love to tour with Neutral Milk Hotel. Or Perfume Genius, who lives here [in Washington state]. I was so psyched about that.

I know the song “Nothing More Than A Body” from your new album was inspired by meeting Jeff Mangum of Neutral Milk Hotel. What was that experience like?

Bighorse: That’s still one of the best days of my life, actually. He walked out, and I just started crying. Then Scott [Spillane] from Neutral Milk Hotel was like, “Put your arms up, put your arms up! Wave your arms like a tree. Breathe in and out, breathe in and out.” And Laura [Carter] from Elf Power was like, “Don’t worry, it’s okay, he’s just a body, he’s nothing more than a body, everyone’s just a body, we’re all just bodies.”

I was like, “can I take a photo with you?,” and he was like, “I don’t really do photos, but I can draw you a picture.” So he drew me this little self-portrait that I have framed in my room now. The chords to “Nothing More Than A Body” are the main chords from the song “Naomi,” the Neutral Milk Hotel song. I got really inspired by that moment.

We were sitting in a Panera Bread one day after “Nothing More Than A Body” premiered on Noisey. I was on my phone checking Facebook and Jeremy Barnes [of Neutral Milk Hotel] liked it. I was freaking out. I went to the bathroom to cry.

Your song “A Little Late” is about not letting jealousy get to you. How do you deal with feeling like you need to compete with other artists?

Mayo: In the long run, that stuff just doesn’t matter. There’s not a pie of success going around, “Well, this person gets this much, and this person gets this much.” You can all be successful.

Pretty much all women are put in this position where we’re made to feel jealous of each other. I’ve definitely been part of that and let myself succumb to that feeling, but it’s good if you can just take that and get over it, and make art out of it. Not everything is competition, and everyone is just doing their own thing. Not everyone is out to get you.