With anyone else it might have been deadly,” Mark Ravenhill says of his collaboration with the arch avant-garde performer Bette Bourne (above) at the Edinburgh Festival. Three separate shows, chronologically performed on consecutive evenings, A Life in Three Acts is the distillation of a series of conversations between the pair that Ravenhill edited into dramatic shape. “I’m in Parky’s chair,” he explains, “looking plain, asking the questions, nodding a lot. It’s Bette that makes it so interesting. His life is amazing.”

Born in 1939, Peter Bourne had an extremely straight acting career until a chance encounter with a gay liberation meeting. He moved into a madcap commune, out of which emerged the “stately homo” Bette and his Bloolips cabaret. With its junk-yard aesthetic and supremely punning show titles— Living Leg Ends, Lust in Space — Bloolips defined the underground drag scene for 20 years. “There’s a need now to re-evaluate, to understand just how radical that moment of awakening was,” Ravenhill says. “Looking at Bette, you think: ‘F***ing hell, you really did change everything.’ He stood up one day and said: ‘This hypocrisy has got to stop.’ It’s a uniquely personal story with an epic, social sweep.”

Ravenhill intends to use special guests to enact segments of the dialogue, though he has “no idea who. People we grab when we get there. I’ll be shoving a script under Stewart Lee’s door. Fenella Fielding, maybe.”

Guerrilla casting is a concept that Ravenhill unveiled at the 2007 festival. He cornered performers after their shows and asked them to appear two days later in one of 16 playlets, Shoot/Get Treasure/Repeat, Ravenhill’s response to the Iraq war. “Everybody had heart attacks but it worked brilliantly,” he says. “People argue that Edinburgh’s dominated by commercial big comedy now, but you do still have thousands of people up there on the hunt for experimental, theatrical experiences. There’s this wildfire effect. People were literally queueing round the block for Shoot . . . And while Edinburgh is no longer the only place where that happens it’s still got the largest concentration of talent and new ideas per square foot. If you can tap into that, and I hope Bette and I do, it’s just incredible.”

A Life in Three Acts is at the Traverse, Aug 18-30