Everyone knowsthat bitin ‘Insomnia’, Faithless’ groundbreaking crossover mega-hit.

That bit after Maxi Jazz’s confessional poetry of sin and sleeplessness. That bit after the edge-of-a-precipice pause that ends the line: “I can’t get no sleep…

Boom! Synthline! That gargantuan riff that sprouts goosebumps, puts hairs on end and sends a shimmering wave of euphoria washing over you, even though it’s Monday morning, you’re sitting in a grey office and you took that pill more than three years ago now.

“I certainly noticed it when we released it,” explains Sister Bliss, the DJ and multi-instrumental musical mind behind the dance trio. “[We thought], ‘People are really going ballistic when the riff comes in!’”

That riff is now 20 years old. Having practically invented ‘the drop’ as we know it today, Faithless are national treasures in their native UK and have legendary status the world over. They are marking their anniversary with an album of remixes, Faithless 2.0.

“It’s quite amazing that it’s endured for so long and had such an amazing response from people over the years,” says Bliss. “Affections can wane, can’t they? We’ve been taken into people’s hearts and that’s an amazing thing as musicians. We could have just totally drifted into irrelevancy.”

Faithless, completed by vocalist Jazz and producer Rollo Armstrong, defined quality ’90s club music while transcending the genre. Tracks like ‘God Is A DJ’, ‘Salva Mea’ and ‘We Come 1’ were born great. “It was a very fertile time for music,” says Bliss. “Less identikit, perhaps. There’s a lot of inventive music around at the moment. There’s also a lot of people using very similar plugins and the same sounds over and over again.

“It’s about the sounds. We didn’t have Logic. Pro Tools only came along by the time of our third album. We love analogue gear. It has a particular sound, it’s wonky and interesting. No two synths sound the same. It wasn’t just using what was fashionable in the moment. Rollo would spend hours going through banks and banks of sounds, tweaking and mucking about on synths until he found a sound he really liked.

“The songs do have a really timeless flavour. You get some dance tracks that don’t stand the test of time. We were very lucky because we’ve always erred away from using cheesy, horrible, nasty, cheap sounds. We also spent a lot of money mixing our music in really good studios at a time when dance music was often made on tiny mixing desks. So sonically our records have something very special about them.”

The idea of a remixes album came to Bliss, real name Ayalah Bentovim, while she was in the bath.

“People have been bootlegging our stuff for years but it’s never been officially sanctioned,” she says. “Laying there I thought, ‘We should celebrate and mark our anniversary in some way.’”

There are some huge names on Faithless 2.0: Avicii, Tiesto, Eric Prydz, Above & Beyond and Armin van Buuren. There are also some serious rising stars in Booka Shade, Claptone, High Contrast and Purple Disco Machine. The support Faithless have received is testament to the influence they’ve had on dance music as we know it today.

“For me, having remixes from some of the biggest names in the business as well as the more clubby underground names, it gives an access point to Faithless that perhaps might not have been there before,” says Bliss. “If your big brother’s got a CD, or your mum or dad, you might think, ‘I won’t listen to the music they’ve got.’ But when you’ve got remixes by artists making a mark on music in a massive way, it’s a really cool thing to bring our music to that generation on their terms. You’ve got to remember, this day and age there’s whole generations who weren’t even born when we started.”

In Faithless’ two decades together (including a brief respite), there have been many memorable moments, like playing Glastonbury’s main stage in 2002 and again in 2010. “We were incredibly hyped both times and had enormous crowds,” says Bliss. “It’s one of those places where that kind of synergy happens. The stars align. The crowd, the air, the weather, the music – everything.”

On performing earlier this year at Exit Festival in Serbia (which features in the Insomnia 2.0 promo video), she adds: “The country has had its fair share of war and strife. I had people telling me they were sitting there while their towns were getting bombed and the only thing giving them hope and taking them through was our music. It’s a total head-fry when people tell you that. There was this insane vibe in the audience, people nearly crying with emotion.”

There promises to be many more memories. Faithless are embarking on a sold-out European tour, with hopes to go further afield, and they’ve just scored their third number one album in the UK.

“It’s been a great feeling to be able to come back and revitalise the band, and the shows have just been off the hook. I feel incredibly grateful to be given another chance to connect with our audience, and they seem pretty happy to see us, so it’s a win-win! Maybe the dance never ends after all.”

Availble through Sony,Faithless 2.0 is out now.