Mutya, Keisha and Siobhan had just become teenagers when development began on what would eventually become the original Sugababes project. The original band was formed in 1998 when they were all still schoolgirls, by All Saints manager Ron Tom, who had previously signed both Mutya and Siobhan as solo artists two years prior. The addition of Mutya’s childhood best friend Keisha, who would join her in the studio after school for moral support, set a new chain of events in motion. “The minute the three of us were in a room and sang together it was very obvious to everyone that there was something special there,” says Siobhan. “I still think that when we sing together.”

The trio christened themselves Sugababes and set about crafting the inimitable sonic imprint that would come to define their artistic legacy. Success, at this stage, had not even crossed their minds. “Fame was very different back then, so you didn’t have the aspiration to become famous as such,” explains Keisha. “We just wanted to sing and we really loved the music we were doing and we wanted people to hear us.”

Sugababes signed to London Records in 1998. Two years of artist development later, in 2000, their debut single, Overload, a singularly fresh slice of distinctly British pop, hit the UK Top 10 hard enough to obliterate pop conventions. “Looking back it’s like, how amazing was our start?” Siobhan says, as if she’s still trying to get her head around it, 25 years later.

The single alone – written with a potent rush of teenage emotion – was enough to pique public interest. But it was also the effortlessly cool edge to their streetwear-inspired look and their casual air of detached nonchalance, atypical for a girl group, that set them apart from their glossy, picture-perfect peers. They attracted a laundry list of world-class creatives to help bring the project to life from producer Matt Rowe, fresh from a stint with the Spice Girls that had netted him six No.1 singles, to Anton Corbijn (noted for photographing icons such as Kate Bush and Annie Lennox) who captured the first images of the fledgling group in 1999 – Mutya, with a pixie cut sandwiched between Siobhan, sporting a pierced brow and Keisha’s punk twist on Bantu knots.

“People were changing their music videos to be very similar to ours, every picture they were doing, they weren’t smiling. It was a whole movement,” Keisha recalls. “We didn’t get what the big deal was. When you’re in it, you’re thinking, ‘I’m just being myself,’ but looking back you go, ‘Oh, OK, so this is why it was fresh and it was new.’” To hear all three speak of this time, it’s impossible not to get caught up in the excitement that still sweeps through them as they recall it. Dancing on the tables at iconic London jazz club Ronnie Scott’s, performing on Top Of The Pops and feeling like it didn’t really happen until they saw it on TV later. Touring up and down the country and around the world. “I don’t think we ever could have understood the cultural impact of that first song until years later,” Siobhan says now.