'I should probably pack, huh?" Thankfully, rather than rushing off to throw a toothbrush and towel into a suitcase ahead of Throwing Muses' visit to Scotland next week, Kristin Hersh sticks around to relive the prolonged gestation of last year's Purgatory/Paradise, the band's first record in 10 years.

A compellingly fractured album of 32 mostly very short songs, released as a lavish hardback book, Purgatory/Paradise is aptly named. "It took us five years to make," says Hersh, from her home in Rhode Island. The time was spent "pulling the limbs off the songs, throwing them back on and expecting them to walk around. This record could have sounded like an idea, and I really don't like ideas. I think it's very important that everything is a response to what the songs want."

Given the band's pedigree, Hersh's claim that it's "the first time we left the studio completely satisfied" is a bold one. One of the pillars of US alternative rock in the 1980s and 1990s, Throwing Muses were, and remain, a unique and beautifully off-kilter proposition. In the UK they were signed to the aesthete's indie label of choice, 4AD, also home to the Cocteau Twins and Pixies. Albums like House Tornado and The Real Ramona were lauded by the music press, but Hersh recalls their early adventures in Britain with mixed feelings.

"I remember thinking, 'Where are all the women?' It was just a sea of boys. We had left a music scene that was vibrant with women and people of colour, and in the UK I was playing to bunch a 19-year-old white boys. It was like, 'What happened?'"

By the time of their most commercially successful records, the mid-1990s releases Red Heaven and University, Throwing Muses' association with Warner Brothers in America meant things had started to sour. "I'm not saying it was all evil," she sighs, "But we were not able to make the music we wanted to make."

Hersh is a significant link in the chain of fearless, pioneering female artists that connects Patti Smith to PJ Harvey and St Vincent. She says she struggled with the baggage of being the band's public face.

"I did my job," she says. "I did interviews, I was articulate, I showed up for photo shoots, but the uglier those got the more I realised that I shouldn't be participating in this industry. You start to wonder what you're doing not just to your own life, but to other people.

"What was I doing to other women to let the industry dress me that way or make me up that way? I didn't like being asked to play a cartoonish role. To bring music down to the level of fashion was something I felt morally obligated to stop doing."

It goes a long way towards explaining why the story of Throwing Muses is not a linear narrative. There have been lengthy pauses - notably the 16 years between 1997's knowingly titled Limbo and Purgatory/Paradise, during which they released only one album - and several line-up changes.

Opening their Glasgow show next week will be Hersh's half-sister Tanya Donnelly, a founder member of the band who left in the 1990s to join The Breeders and then form Belly.

"Tanya is the opener for the whole tour," says Hersh. "It's sweet, we play encores together. It's family, it's comfortable."

Hersh was one of the first prominent artists to embrace crowd-funding.

Another reason why Purgatory/Paradise took so long is that it was "listener-supported". "I was working whenever I could raise the funds, like making an independent film," says Hersh. With the record industry in steep decline, she believes "there's an opportunity to grasp something. It allows for some reflection, which in this industry normally isn't allowed. When we were recording for Warner Brothers we certainly had a lot more money, but we didn't have that objectivity. You had to go in and know exactly what you wanted to happen, and then you left full of regret."

Hersh has talked previously about the extraordinary source of her writing. Misdiagnosed for years as schizophrenic, then as bipolar, she describes songs as unwelcome intruders, appearing without her permission or conscious participation. "I didn't write them on purpose," she explains. "I used to hear sounds at 4am and I'd feel electricity on my skin. Sometimes I would ask my husband, 'Is that music? Is it a noise next door?' He would hold my arm and say, 'I can feel it. It's a song.' I well up saying that, because I don't like fuzzy human perception, I like vision to be piercingly accurate. This was something I never understood, and it was often a torture."

She was finally diagnosed with post-traumatic stress disorder, which has been treated successfully. "When it was cured it revealed an alternate personality, and that personality was music. That was what had been knocking on my head all these years and making me so sick."

Since her health was restored last year she hasn't tried to write, although with two albums by her art-noise band 50 Foot Wave "in the can", and two solo records also completed, there is plenty more Hersh to come.

"I don't really know what the writing process is like now, or if there is one any longer. It may be that I don't need music to happen anymore, or it may be that I'm completely present for it when it does." She pauses. "I guess it's good, but it's so freaky. I don't like freaky."

Throwing Muses play Oran Mor, Glasgow, on September 17. Purgatory/Paradise is out now via The Friday Project