There have been many highs in the Brighton-based Hartnoll brothers’ long career.

Orbital were pushed up the bill at Glastonbury 1994 and closed the main stage after Björk had played. The Acid House duo arguably introduced electronic dance music to Michael Eavis and to the festival. They got people dancing and now there are whole fields for dance music.

Last year they were joined at Glastonbury by Matt “Doctor Who” Smith for their track which rewired the TV show’s original theme.

And Phil and Paul, residents in the city for almost 16 years, have remixed music by their heroes, electronic pioneers Kraftwerk, and worked on music for Madonna.

But what is really special? Getting Professor Stephen Hawking to don a pair of torch glasses.

“I can die tomorrow and I’ll be happy,” Phil says, musing on how he talked the scientist into wearing a pair of Orbital’s trademark specs for the Paralympics Opening Ceremony 2012.

“We had him speak into a vocoder and put him through a pitch bend,” he continues, recalling Hawking’s fun side and how, despite the paralysis, he managed a little smile.

“I sent him a radio edit of the track with him singing on it afterwards because a tribute to Ian Dury interrupted our music.

“He was adamant we should release it.”

The brothers were first working as Orbital (a name inspired by the London Orbital, the M25) between 1989 and 2004. They reformed for a one-off show – “20 years after Chime” – at The Big Chill in 2009.

“The response blew our minds, so we did another gig and then another gig and that lasted for a year and half. There was no grand scheme.”

Eventually, after finding the lie of land satisfactory, the brothers wrote new material.

“It was easier than before. We worked hard but it was like our first album again, with no constraints, no worries, no cares.

“That comes across in the sound. It’s one of the best albums we’ve written. It’s all current.”

Phil contrasts it to 2004’s Blue Album, which was the catalyst for the split.

“That’s when we thought we can’t do this any more and we’re never gonna get it back. We threw the baby out with the bath water.”

He admits they needed a full stop. They’d been too close for too long. But things have turned – they’ve just returned from playing to 12,000 fans in Japan.

Next to the giant venue hall were iPads on sticks in a future technology exhibition. Sounds like a dream for two technophiles who bring a studio’s worth of gear – from synths and sequencers to drums and laptops – to shows.

“Paul is more nerdy,” jokes Phil, who says his brother has a mountain of drum machines and compressors in boxes ready for the road.

“We use remote control iPads and send midi messages and audio loops through Ableton.

“We improvise with the arrangements, which are sent to the mixing desk like a big mash, and there is room to manoeuvre.

“It’s basically a studio on stage and we are running it all live, a song could last a minute or an hour.”

Dancefloor to studio

They demo’d and road-tested new tracks from Wonky, the eighth studio album (released in April), in their club sets as DJs.

The title track came straight from the dancefloor to studio and only missed a vocal.

“We weren’t conscious about getting a young singer. It was more a case of who fitted. We asked Kate Bush but she was busy,” he jokes.

Grime MC Lady Leshurr laid down some vocal lines she’d penned on her iPhone in a pitch-black studio.

“She wrote the lyrics and we told her what we wanted style-wise. She rattled it off on the last day of recording and Wonky was born.”

Zola Jesus, a gothy singer who combines an interest in opera with a love for industrial music, sings on New France. “We are Cocteau Twins fans from way back when so we always gravitate to female wailing vocalists. That track needed a female vocalist and someone said Zola Jesus would fit.

“As soon as we met we got on like a house on fire. She wailed away for two days and we got tonnes of material.”

Among the signature vistas and euphoria are contemporary touches such as the reworking of old favourite Satan into a dubstep rumbler called Beezledub, with slowed bpms and fatter bass.

One Big Moment is their “big bang” opening and samples counter-culture quotes. A 1959 interview with Bertrand Russell is a statement of intent: “Love is wise, hatred is foolish, in this world which is getting more and more closely interconnected...”

“We can’t help but put in lovely little quotes especially when so much shit going on in world,” says Phil, who moved to Brighton just before the eldest of his three children was born.

“We are old hippies at heart: Make Love, Not War.” But even for old hippies new material is essential.

“There came a point where we had to decide if we wanted to be like Status Quo, rocking around world for rest of our lives or not.

“We were enjoying it so much we thought we either call it a day now permanently or we carry on playing live – and that requires new material.”

It had to be an album because they are staunchly old school. They called up long-time friend Mark “Flood” Ellis, the electronics whizz who produced Depeche Mode, Erasure, Nick Cave, U2 and PJ Harvey. He invited the brothers to techno heaven.

“He had some tricks up his sleeve and has a different technique. He is synth collector and has banks and banks of old analogue synths. When we went to his studio it was like a sweet shop.”

Even as far back as the 1990s, and classics such as Chime and Belfast, Orbital never wrote tracks specifically for the dancefloor. The pair have always talked about being moved by melody and harmony. They stop when something gives them the “ooh moment”.

Phil says Chime was the most impulsive track they ever wrote.

“We didn’t have a clue. It was a case of get it out of your head as quick as you can, the quicker the better, and that catapulted us in to making an anthem.”

  • Brighton Dome Concert Hall, Church Street, Tuesday, December 11. Doors 7pm, tickets £24. Call 01273 709709