Andy Bell’s Twitter account declares that he is ‘loving 2014 so far’. It’s a productive time for the flamboyant singing half of Erasure, with collaborations aplenty. But he can explain all that. ‘It’s the year of the horse,’ he says. ‘I looked it up and it said “you must work this year”. You know those feast and famine periods? This is one of those work, work, work periods.’

So, he has worked with dance duo Shelter on their new album iPop, worked with his Erasure partner Vince Clarke on an album for release later this year and worked with poet, performance artist and archivist Barney Ashton on his Fringe debut, a dramatic song cycle (plus accompanying album) rakishly titled Torsten the Bareback Saint.

The eponymous hero is a Dorian Gray figure, only less malevolent and narcissistic. According to the production notes, this ageless adventurer, old in years but young(ish) in looks, finally made it out of his endless adolescence with a growth spurt in the late 80s. Now 42, he’s looking back at key events in his life to date, while lamenting the impossibility of sustaining relationships lest his unsettling secret be discovered. ‘He’s very vulnerable but he has this armour as well,’ says Bell. ‘I don’t see him as a victim at all. To me, it feels like you are reading through Torsten’s diary and each song is a certain period when he’s written down what he’s going through at that time. He seems to be a bit like Doctor Who where he can just travel wherever he wants to.’

Bell also compares him to one of the musclebound characters from the homoerotic artwork of Tom of Finland. ‘Because I’m blond and have blue eyes, maybe I fit the character a bit. He’s not necessarily gay; he’s slept with all kinds of people. I only had one girlfriend but that was enough for me to relate to in some of the songs. Quite a few sound like stories from my own life. Some of the songs are very London-ish, hanging out in saunas, stuff like that. I don’t know if I’m just weaving myself into it but that’s how it feels to me.’

Bell, who celebrated his half-century earlier this year, has also been quoted as stating that ‘I’ve never felt old, ever’ but that’s maybe taking the comparison too far. It is also tempting to compare Torsten to 2011 Fringe hit Ten Plagues, a modern operatic song cycle about the Great Plague of London, written by Mark Ravenhill and performed by Bell’s queer pop peer Marc Almond. However, the music in Torsten is a more varied mixture of European cabaret, rock opera, jazz and torch songs.

Bell has dipped into these genres for one-off projects in the past. In the early 90s, he sang the part of Montresor in The Fall of the House of Usher, a rock opera written by Peter Hammill and Judge Smith of prog rockers Van der Graaf Generator, and played the title role – for one night only – in the play The Night We Buried Judy Garland. More recently, he appeared on reality TV show Popstar to Operastar where he says he was ‘a rabbit caught in the headlights. I got that fear live on camera. But I think I’m much more ready in my own skin to do something like this.’

Nevertheless, he has described Torsten as the most challenging role of his career. ‘You feel naked. There are no bells and whistles, and it’s not your own songs. When I’m doing Erasure, I’m in my comfort zone. This is something completely different. I don’t think people are going to be offended but there’s quite a lot of swearing and visceral lyrics. It’s quite rude but I’m really enjoying it because I’ve got a clean-cut image.’

There has always been something puppyish and playful about Bell’s stage persona. He reckons his naivety even played a part in first getting him the Erasure gig when ex-Depeche Mode / Yazoo songwriter Vince Clarke held auditions for a new singer.

‘I didn’t know how to hold the mic properly,’ he recalls. ‘I hadn’t really sung falsetto and for some reason it just sprang out of my mouth on that day. I think it took us both by surprise.’

From the start, he was completely open about his sexuality, and revealed his HIV-positive status ten years ago. His long-term partner and manager Paul Hickey, who died in 2012, was also HIV-positive. Although Bell takes a relaxed each-day-as-it-comes approach to his life and career, he doesn’t take success for granted, even after close to 30 years in a globally successful pop band. ‘When you do pop, it’s quite superficial really,’ he says. ‘After a while, the star fades and you have to get used to that. It’s not about you, it’s not about your ego, it’s about being open. I think you have to do something else to broaden your artistry.’

Which leads Bell to 12 nights at the world’s biggest arts festival. Although Erasure have played in Edinburgh numerous times over the years, Bell has never been to the Fringe, even as a punter. ‘Vince has been; he says it’s really mad, everything going on. He thinks it’s so cool that I’m doing this. I hope he’s going to come and see me. I can’t wait; I didn’t realise how much I would enjoy being in theatres, because I’m not a luvvie or a great fan of West End musicals. But I just love being in the theatre space.’ I don’t like to tell Bell that he will be performing in a university lecture hall now he has a taste for the boards.

Ashton intends to continue Torsten’s story over a couple more episodes and Bell, for his part, would like to continue in the role. ‘I said to Barney “when it comes to the movie, don’t sack me when they get Ryan Gosling to do the part because I’m too old by then”. It would be brilliant to do it when you’re 80.’

Torsten the Bareback Saint, Assembly George Square Studios, George Square, 0131 623 3030, 5–16 Aug, 6.30pm, £16–£19.

Andy Bell of Erasure is ... Torsten The Bareback Saint (Official Trailer)