FOR nearly 30 years Andy Bell has served as the charismatic frontman of synthpop heroes Erasure.

Yet the 50-year-old still struggles with shyness onstage.

The duo - Andy and synths cohort Vince Clarke - are back with a new album, the Violet Flame, and a sold-out gig at the O2 Academy tomorrow night.

But Andy says: "I still am quite shy when performing.

"It depends hugely on your mood. You get used to it after a while but it can still creep up on you every now and then."

The Violet Flame marks Erasure's 16th record, and has been one of their biggest hits in years, reaching the Top 20 for the first time since 2003's Other People's Songs.

If last year's Christmas themed Snow Globe showed the two-piece at their most fragile and eerie, with a series of wintery originals and festive covers, then the Violet Flame is a return to euphoric dance pop.

The duo aimed right from the start of recording to go in that direction, aided by their studio location in the sweltering Miami.

"We wanted to make more of a dance record this time," he says. "Both Vince and I have been doing a bit of DJing so we've got 'disco' in our bones now. It was just a relaxed vibe."

They also worked with a different producer, choosing Richard X, from Lancashire, who's worked on a host of hit singles by the likes of Kelis, the Sugababes and Libery X.

"It's always good to have an outsider involved," Andy reckons.

"Richard brought a different perspective and also a time frame, without which we'd never stop recording."

Andy is based between London and Miami, but has been no stranger to Scotland this year.

In August he was at the Edinburgh International Festival, where he was performing in the one man show Torsten The Bareback Saint, a risqué show about sexual longing and discovery.

The soundtrack has since been released as a solo album, but the challenge of taking to the stage each night certainly had an impact on Andy.

"It was an amazing experience," he says.

"Although it wasn't quite full-on talk acting because I sang the whole way through, but I loved delving into my subconscious and digging up old wounds to make the character seem real."

Given they'll celebrate three decades as a band next year, it's no surprise that Andy's used to visiting Glasgow.

"Playing in Glasgow has always been special for us," he adds. "The fans are incredibly enthusiastic and welcoming, so we have a blast there."

l Erasure, O2 Academy, tomorrow, sold out, 7pm.