For nearly 25 years, one of the most instantly recognizable sounds and looks in electronic dance music has belonged to Orbital. Which isn’t to imply the U.K.-based duo has been hitting the same notes all that time. Brothers Phil and Paul Hartnoll have openly embraced the ever-changing moods of club culture during their lengthy and still-thriving career. 

Yet if you were to put Orbital's discography on shuffle, signifiers would keep popping up: pulsating synth lines; steady 4/4 beats; sultry female vocals; major-chord melodies that linger in the brain for days. And if you check out footage from Orbital's most recent series of gigs, you'll see the same thing you would if you were to cue up the DVD of the duo's highly revered performance at the 1994 Glastonbury Festival: Phil and Paul standing behind a bank of equipment, their signature flashlight glasses framing their close-cropped pates as they bop in time with the music. 

The pair doesn't shy away from this notoriety, either. When the Hartnoll brothers made an appearance at the opening ceremonies for the 2012 Paralympic Games, they gladly fitted Stephen Hawking, who was being sampled in the track the two performed, with their trademark specs. And live sets often dip all the way back to "Chime," the acid-house classic that kicked off Orbital's career in 1989.

For as deeply ingrained as the Hartnolls' work has been since the two began recording together ("Chime" hit No. 17 on the U.K. pop charts, and three of its full-lengths cracked the top 10), the pair hit a creative wall about eight years ago. 

"We felt we were sort of lost," says Phil Hartnoll, speaking from his home outside London via Skype. "We weren't really feeling what we were coming up with. It would've been easy to carry on, really, but we felt, 'Well, we're not feeling it, we're not grooving it.' So we felt it was time to stop doing it.” 

But just as the two rarely sit still, in live performances and interviews—Phil kept moving out of the frame of his webcam during our conversation—the Hartnolls quickly moved forward. Paul released The Ideal Condition, a well-regarded orchestral-based solo album, in 2007, and Phil started a new duo and kept up a steady schedule of DJ gigs. 

The two might have continued on their separate paths were it not for an offer in 2009 from the Big Chill, another U.K. music festival, to perform a set in celebration of the two decades since the release of “Chime.” 

"That spiraled into people wanting us and booking us," Phil says. "That carried on for a year and a half, and then we came to a point going, 'All right, we really can't be rocking around the world with old tracks. We've either got to say, "That is it," or do some more music.'"

Opting for the latter, Orbital knocked out a new single in 2010, and followed it this year with Wonky, the duo's eighth studio album. Recorded with renowned U.K. producer Flood (Depeche Mode, the Pains of Being Pure at Heart), Wonky pays heed to Orbital's earliest acid-house influences while also dabbling in the wobble of dubstep ("Beelzedub," is a caked-on remake of "Satan," one of the group's biggest singles) and stringy bits of minimalist house. 

Now comes the fun part for Orbital: hitting the road for an extensive tour, a scenario where the band has thrived from the beginning. 

"It's always been an important thing for us," Phil says. "It was a way of getting the music out there, just the same as an indie band. Build up a following. And the way we play live, basically we set our studio up onstage, so we can improvise with the structure of songs and see how it feeds off the audience. It's great. You get a chance to see the audience's reactions and feel it with them.” 

SEE IT: Orbital plays Roseland Theater, 8 NW 6th Ave., on Friday, Sept. 28. 9 pm. $30. 21+.