Life is all about change, says Sleater-Kinney’s Corin Tucker. She would know. Last July the veteran indie threesome shrunk by a third when drummer Janet Weiss announced she was departing after 25 years. A month later, the band put out their new album, The Centre Won’t Hold. It was the fruit of their high-profile collaboration with art popster-turned-producer St Vincent and marked a dramatic shift in their sound. Weiss’s exit and St Vincent’s entry into the frame were not unrelated, it was widely suspected.

“I’m just grateful for playing music,” says singer and guitarist Tucker. She seems a bit worn after months answering variations of the same question: why did Weiss leave? “One of the things about getting older and looking at life is that you realise that change will happen. It just will. It will be difficult. That’s true whether it’s personal or political or just in life.”

Weiss might have a different perspective. “It’s time for me to move on,” she had tweeted on July 1, weeks after Sleater-Kinney had released a new single, ‘Hurry On Home’.

She later elaborated, explaining she felt she had been sidelined in the studio. The dynamic between her, Tucker and third member Carrie Brownstein had shifted during the recording of The Centre Won’t Hold.

“The rules changed within the band, and they told me the rules changed,” she told drummer Joe Wong on his podcast, The Trap Set With Joe Wong. “I said, ‘Am I just the drummer now?’ They said yes. And I said, ‘Can you tell me if I am still a creative equal in the band?’ And they said no. So, I left.”

“It’s really important to look at the positive and try to be more accepting of change and wish people well,” Tucker (47) tells Hot Press diplomatically. “For me, it’ s a case that I’m grateful we’re playing music and that I get to be in this band. I try to look towards the positive.”

Still, the fact is Sleater-Kinney were a trio from their formation in the university town of Olympia, Washington in 1994 until last July (they took a hiatus between 2006 and 2014). Now they’re a duo. True, on tour they are supplemented by other musicians. But ultimately it is just Tucker and Brownstein (who were briefly in a relationship in the ’90s). Does it feel different when it’s simply the two of them?

“I think that… you know… I think that I just really enjoy being in this band. I enjoy the music that we’ve made,” she continues. “There is definitely a difference. I feel we had to move on for our North American tour. It actually came together to be a strong tour. The live shows were great. We had a good time. That was my take away from it.”

The real shame is that the fracturing of the original line-up overshadowed a fantastic album. The Centre Won’t Hold is dark and roiling. Sure, you can discern St Vincent’s influence if you’re looking. It’s there in the sometimes brutalist interplay of melody and squalling guitars. Still, for all the changes, the LP is classic Sleater-Kinney.

This, in other words, is progressive alt-pop delivered with a snarl and a social conscience, but with riffs to swoon over and songs that growl and clatter euphorically. It’s a bit of an instant classic and fans will be counting down to hear Tucker and Brownstein reprise it at Vicar Street at the start of March.

Sleater-Kinney are among the most iconic alternative groups of their generation. They came up just as grunge was bringing the genre into the mainstream, having formed in the aftermath of Kurt Cobain’s suicide. Critics were soon praising their blend of post-punk agitprop and third wave feminism. In the context of the ’90s – still backwards compared to today in many aspects – they were a landmark.

“If Sleater-Kinney wanna be our Simone de Beauvoir,” music critic Anne Powers said of their 1997 third album, “Dig Me Out proves they’re up to it.”

They’re still fighting the righteous fight. As the title attests, The Centre Won’t Hold is grounded in the upheavals we are all suffering through, and the dangerous rise of populism both sides of the Atlantic.

“It’s the age of anxiety that we’re living through right now,” agrees Tucker. “In the sense of a loss of a feeling of security. There are a bunch of aspects to it.”

She is talking to Hot Press the week the Iowa Caucuses descend into chaos because of a malfunction in the Democratic Party’s untested new voting app. It is a reminder, says Tucker, of the menace posed by Big Tech.

“There are political aspects to the present instability. There are also technical aspects. It rang so true with regards to what happened last night [the Democrats’ app SNAFU]. We put ourselves in the hands of this technology that is supposed to be an advantage for us. And it’s not: it’s not well built, it’s not safe. And we put way too much trust in it.”

Within a few days, as the digital smoke clears, it will have become obvious Bernie Sanders was one of the big winners in Iowa. That will please liberals in Oregon where Tucker live with her husband, filmmaker Lance Bangs, and their two children Marshall, aged 17, and Glory, 11.

“There are a lot of people for Bernie,” she says. “But also a lot of Warren supporters. And some for Andrew Yang [who would subsequently drop out].”

She is cautiously optimistic Trump will be voted out. But realistic too. “It is definitely true that he might be re-elected. We have to prepare for that. There’s a good chance. I don’t know what to say. It’s a difficult time.”

As she speaks, her bandmate Brownstein (45) is at the Sundance Film Festival with St Vincent. They are premiering their movie The Nowhere Inn. It’s an arthouse comedy parodying the lunacy of touring. Sleater-Kinney and St Vincent have evidently struck up a close connection.

“St Vincent is a fascinating person,” says Tucker. “She is very talented in a lot of different ways. I was really interested in her take on things. And I would love to see more women producing music. Traditionally it’s been more men in that role.”

Brownstein is no stranger to the screen or to mainstream acclaim. During Sleater-Kinney’s 12 years off she wrote and co-starred, with Fred Armisen, in hipster satire Portlandia. Tucker, meanwhile, hasn’t seen The Nowhere Inn. She suspects she would enjoy a film that conveys the thrill, the madness, the boredom of life on the road.

“You have to live for that hour on stage,” she says. “It has to be the thing you were meant to do on this earth. The travel is brutal. You have to love music to do it.”

• The Centre Won’t Hold is out now. Sleater-Kinney play Vicar Street, Dublin on March 1.