What: Purity Ring

Where: First Avenue’s mainroom, 701 N. First Ave.

When: 8 p.m., Friday

Cost: $10 in advance; $12 at the door

Canadian duo Purity Ring’s ascent to popularity last year was close to meteoric, but that’s not much of a surprise. Megan James and Corin Roddick make catchy, experimental pop flirting with dubstep, a genre more popular than ever.

This past summer, their debut album “Shrines” was released by 4AD. They co-headlined a night of the Pitchfork Music Festival in July and are now embarking on a world tour including a stop at First Avenue’s mainroom tomorrow night.

“It’s definitely happened faster than we expected. We weren’t expecting anything really,” Roddick said. “It has felt pretty natural though. People just hearing our stuff and sharing it with their friends online.”

Until the release of “Ungirthed,” a concise and delicate pop gem, in early 2011, Roddick had little success as a songwriter. There was a good reason for that.

“That was the first song I ever wrote,” Roddick said. “I had always been a drummer in bands and wanted to try to actually write more than just percussion. That was the first song that I actually finished.”

Two weeks after they posted it on the internet, “Ungirthed” was featured on numerous music sites and blogs.

“At that time, it was the only song to our name,” Roddick said. “But it was just exciting that people wanted more. Looking back on it now it would have been easier if we wrote a handful of songs and then come out with them all. But it was just really cool. We didn’t know how to react.”

They did not rush to meet the demand. “Shrines” was released in late July, a year and a half after that first song. None of that time was wasted on songs that didn’t make the cut.

“The ten that made the album are the ten we wrote,” Roddick said. “Some people can just pump out songs, like write a song a day, and at the end of it narrow it down to ten. I can’t come even close to finishing a song if I feel like it might be a B-side. … I want everything to be up to a certain standard.”

Purity Ring approaches their live show with that meticulous attitude as well. James sings while Roddick’s sounds and samples radiate from orbs that light up as he hits them with drumsticks. They built the mechanism themselves.

“That instrument came from thinking about how to creatively perform electronic music and have clear visual feedback for the sounds that are being created,” Roddick said. “The audience hearing the sound and seeing the orbs light in certain ways … I want it to be something like watching a guitar player strum a chord and then hearing that chord.”

Though he and James plan on continuing to evolve their music and live show, experimentation is not their first priority.

“The sounds that I gravitate toward are very listenable. Things that aren’t hard on the ears,” Roddick said. “I think in the realm of pop music, there’s a lot of room for experimentation. But I always want to keep it grounded in pop.”