A lot has changed since All Saints first charged onto the scene in 1997. Back then, Tony Blair had just won the election, Oasis were at number one with Be Here Now, and the world's biggest website was a page full of dancing hamsters.
Pop music was in the doldrums - this was the year of Barbie Girl and Gary Barlow's solo album - so Shaznay Lewis, Melanie Blatt and sisters Natalie and Nicole Appleton were a welcome breath of fresh air.
Positioned as a credible alternative to the Spice Girls, they wrote their own material, dressed in street-smart clothes and shunned the chirpy choreography of other girl groups (their signature move was an apathetic shrug of the shoulders).
But it was a difficult time to be a woman in the male-dominated music industry.
Female pop stars were expected to dress provocatively - a revealing photoshoot for FHM was a rite of passage - and All Saints, never knowingly in possession of a smile, were frequently dismissed as "difficult" or "sulky".
It was unfair and it was sexist, protests Melanie.
"A lot of Britpop groups at the time would act very arrogantly and very stroppy, but that was never seen as a negative thing," she says.
"We weren't half as bad - but if we didn't want to smile one day, or we weren't really interested in doing an interview, we'd be labelled as stroppy cows."
The sexism spilled over into their TV appearances, and the band shudder as they recall a traumatic Top of the Pops taping.
"They were filming images of us to use as a backdrop," says Shaznay, "and they wanted us to take our tops off."
The producers, they explain, wanted to shoot the band from the shoulders up, giving the impression they were performing in the nude.
"The vision was that we looked naked and we didn't want that vision," adds Natalie. "But because it was such a huge show, we were told 'if you don't do it, you don't get to go on the show,'" says Melanie.
"The girl that worked with us was in tears because she was trying to fight our corner," Natalie continues. "We ended up having to compromise with the producers. We dropped our tops to here [indicating her armpits] so it would look like we were topless."
"We did it but we were stroppy about it," says Nicole. "Again, we got labelled as being difficult."
A BBC spokesman said: "We're not able to comment on something that is alleged to have happened nearly 20 years ago, but today we seek to ensure that everyone working at the BBC does so in an environment in which they are comfortable."
Nineteen years later, squeezed together on a couch in West London, the band are anything but stroppy. They trip over each other's words, trading jokes and locking their band-mates out of hotel rooms as a way of surviving a long day of press interviews. Even the Top of the Pops incident is laughed off.
"These days it'd be like, 'you want to see me naked? OK! Sure!" jokes Natalie. "I'll take my trousers off this time!"
Their camaraderie is something of a surprise. After two multi-platinum albums, the band imploded in 2001 over the disputed ownership of a combat jacket.
"Being in a group is like being in a marriage, and right now we are going through a really rough time," Nicole said shortly before the split. A subsequent statement confirmed the band were "on ice" in order to "clear the air between themselves".
The former schoolfriends didn't speak for years, but bridges were built during a brief reunion in 2006, and strengthened on a nostalgia tour with the Backstreet Boys three years ago.
"But we still get asked about the jacket every day," laughs Nicole.
Following the 2013 tour, the band were keen to continue, but their management suggested they needed new material before going back on the road.
"Shaz was nominated to write the album," says Natalie, "but there was no master plan, no-one telling us, 'this is the vision we have for you'. There was no pressure. And she pulled out an amazing record."
After a year in the studio, All Saints' comeback was announced on New Year's Day via Twitter but the response was more one of curiosity than enthusiasm until the band unveiled their new single on Chris Evans's Radio 2 Breakfast show.
One Strike recalls the dreamy, blissed-out sound of their number one hit Pure Shores, with the quartet's silken harmonies provoking a rush of 90s nostalgia.
"It was a natural first single," says Shaznay. "We didn't really even have to discuss it that much. It was the first song we recorded together again. It's just a great beginning."
Although written by Shaznay, the lyrics were triggered by Nicole's divorce from Liam Gallagher. The couple split in 2013 after the Oasis star phoned his wife on holiday and confessed to fathering a child with another woman. One Strike refers to that phone call, and "how your life can change in an instant".
"Like everybody's seen and heard [in the press], I was away when stuff went down," says Nicole. "I had to pull myself together because I'd got my family and kids around me but, after a couple of days of letting it sink in, I was on the phone with Shaz for a long time, just explaining [how] I was getting through it. You know, having to stand up to it, instead of becoming some sort of victim.
"The next thing I knewâ€¦ she played [One Strike] to me and I was singing along. Then she said, 'were you listening to what the song's about?' and suddenly the penny dropped and I was like, 'oh my God. It's our phone call!'
"The thing is, for me, I've kind of handled everything with dignity and the support of the girls and my family. I think the song represents that very well. I don't feel sad when I hear it, I feel quite liberated. It's a very positive song. It's just great. It really captured the moment."
As Nicole tells this story, Shaznay quietly watches her with the protective gaze of a mother. At 40, she is the band's youngest member - but the others look up to her as the leader; the one they turn to for advice and, says Nicole, "a great listener".
"She writes poetry," says Natalie. "Sometimes, when I start to think about the things she's written, it blows my mind."
In the 10-year gap between albums, Shaznay has continued to work as a songwriter, collaborating with the likes of Little Mix and Sugababes  - so how did she relocate the trademark All Saints sound?
"I actually can't explain it," she says. "I think one of the fundamental ingredients for the sound is our voices together and that sort of slotted back into place."
However, she says, everyone's voice changed in the intervening years, meaning the arrangements have to be re-written for their upcoming tour.
"I used to do the high harmony, now I do the low one," explains Melanie. "My balls have dropped."
Not for the first time, the band cackle with laughter, happily unencumbered by the media training that dictates most modern interviews.
"Artists tend to be more careful of what they say now, because it can move into the stratosphere so quickly," says Shaznay. "But while it's understandable, I think it's a shame - because you lose the essence of who an artist is. You don't get a real feel for anybody, so everybody becomes generic."
Perhaps that's the essence of All Saints' appeal - they're not caricatures, but real women who embrace their strengths and flaws.
So, is this reunion the start of a new chapter?
"When we'd finished this album we could have easily carried on because, by the time we got to the end, we'd started to explore different sounds," says Shaznay. "I think if we hear more material that we're inspired by, we'll definitely write more."
"But we're in no rush," cautions Melanie. "We're taking our time."
Surely they won't wait another 10 years, though?
"It'll take me that long," says Nicole, "to get off this couch."
All Saints' album Red Flag is out now on London Records.
Reformed pop group All Saints discuss their new album, and recall the sexism they encountered in their first flush of fame.