American electro-pop band Twenty One Pilots are well known for their live shows, despite comprising only a drummer and a keyboard player.

How do the pair - who play instruments that usually require them to be stuck in one spot - electrify their concerts?

Singer-pianist Tyler Joseph and drummer Josh Dun perform all sorts of high-energy stage antics in between playing their instruments. These run the gamut from the weird to the wacky to the wonderful - leaping off pianos, climbing stage scaffoldings, crowd surfing, wearing skeleton masks and doing back flips.

Speaking to Life in a telephone interview ahead of their show here next Thursday, Dun, 27, says: "When we first started out as a band, we had no other option to get people to listen to our music. So the best way was to go out and play a show. Tyler and I both love performing and being on stage."

Nonetheless, they do nurse self- doubt every now and again.

Dismissing their seemingly self-assured personalities on stage, Dun says: "Every night, Tyler and I appear to walk out like two extremely confident, maybe even arrogant guys. People look at us and think we are under control. But many times, I would say that is false.

"We both think to ourselves, 'Am I good or cool enough to do this?' The fact is that there are just two of us and we wonder whether our show will be interesting enough for people to enjoy and tell all their friends about."

Their feelings of inadequacy served as the inspiration for their latest studio album, Blurryface, which soared to the top of the Billboard Charts after being released in May. The album's lead single, Tear In My Heart, debuted at No. 8 on Billboard's Top Rock Songs Chart, while another track, Fairly Local, reached No. 1 on iTunes' Alternative Chart.

Dun reveals that Blurryface was actually a character the band created to personify the insecurities they face every day.

"Whether it is within songwriting, performing or walking on stage, we both have insecurities. We gave this character the name of Blurryface so we can address these things and be able to feel like we are fighting a tangible battle that is winnable," he says.

"We are trying to be intentional about the things that affect us. As I talk to more people, more of them have latched on and recognised that they share these internal battles as well."

Twenty One Pilots were formed by Joseph, 26, and two other friends, Nick Thomas and Chris Salih in Columbus, Ohio, in 2009. They put out their self-titled debut album in the same year before Thomas and Salih left, citing busy schedules.

Dun joined Joseph in 2011 and the two released the band's second album, Regional At Best, which yielded the breakout hit Holding On To You.

They were subsequently signed to American record label Fueled by Ramen in 2012 and released their third album ,Vessel.

The band's name comes from the play Twenty One Pilots by American playwright Arthur Miller, about a man who commits suicide after he causes the death of 21 pilots.

Given that Blurryface is their most commercially successful album to date, perhaps the duo's recurring insecurities will soon be a thing of the past.

In fact, Dun promises they might bring even more to the stage.

"We're always going to have a pretty large emphasis on our live shows. It's not just so people can like us more, but it's because we need to do it. We're going to continue to play as hard as we can and try to be even more creative and outdo ourselves."