Jack Parlett is fidgety and smilingly apologetic when I hail him down in Starbucks, narrowly averting the disaster of his approaching the wrong person. With his checked shirt and ear piercings, he has just the right air of post-punk that I’d expect from the director of Cowboy Mouth, a play written bizarrely both by and about Patti Smith and Sam Shepard and their destructive love affair in 1970s New York.

All set for an intense briefing on the weird and wonderful historical background of the play, I’m surprised when Parlett doesn’t mention this at all: "On the surface, it’s about these two people, one of whom is a man with a wife and child, the other an escaped mental patient who’s apparently kidnapped him. They’re holed up in a room together, having conversations about their existence, their relationship, the world outside." It’s pleasing, actually, to see a director so primarily concerned with the meat of the play itself, rather than getting bogged down in its context.

"I guess it is autobiographical", Parlett muses when I bring up Smith and Shepard, though this doesn’t seem the first thing that jumps to mind. Instead, Parlett enthuses about the play’s significance as a piece of musical history: "They’re both avid lovers of rock n’ roll music. It’s a proto-punk play, about finding a way into some counter-cultural movement." Parlett’s love of Patti Smith is gloriously exuberant: he speaks rousingly about her as a frontierswoman for androgyny, blasting stereotypes about female musicians; but also, crucially, discovering her own musical agency and capability through her abandonment by Shepard: "When the play is over, she’s in a situation where she doesn’t have the man to be her protégé, but must be her own."

There must be something fascinating, though, about the manner in which the play was composed and first performed: Smith and Shepard wrote the play in their hotel-room-cum-love-den at the Chelsea Hotel, about a situation that exactly replicates their own with the exception of their changing their names to Cavale and Slim respectively. The pair staged the play in 1971 at the American Place Theatre in New York, in a double-bill alongside another play starring Shepard’s wife, ironically as a Patti Smith-esque character. A weirder situation couldn’t be imagined. "It’s a really strange play, I should probably say that as a disclaimer," Parlett concedes.

And yet Parlett clearly wishes to resists a reductive, sensationalist approach to the play despite its shocking context: "It’s not a soap opera with a mistress, wife and love-rat. The focus is on these two characters. We never learn the wife or child’s name. They’re part of the outside world that never really intrudes." The focus then, is on the maelstrom of a relationship that is ultimately unworkable. The tragic kicker is that isn’t a spoiler, it’s historical fact: on the second night of the 1971 run, Shepard fled back to his wife and child. "They knew their relationship was going to end[…]I can’t imagine how horrible it must have been to write it. They were inscribing their own pain."

I wonder whether there might be something alienating about a play so intensely self-centred? Parlett agrees: "It’s not a traditionally relatable story. It eradicates the impulse to like them, feel sorry for them, or understand exactly what they’re saying." But Parlett clearly doesn’t want his audience to relate to his characters in an easy way: "There’s no need to relate immediately. There’s an interesting voyeurism when you’re not sure who they are, or what they mean". It’s this very intensity and claustrophobia in Cowboy Mouth that Parlett hopes the Corpus Playroom, in all its dingy awkwardness, will bring out.

Bringing down the intellectual tone a notch or two, I bring up the Lobster Man. This is the bizarre, quasi-hallucinatory figure who marks the play’s radical rejection of any pretence to realism, and whom Parlett has found something impressively worthwhile to say about: "It’s easy to write it off as a drug hallucination. In the end, he has a much larger significance, which, though it probably comes out of an illusory consciousness, is Christ-like and redemptive. That’s how they translate the world around them. The lobster has a cultural significance." If he can make a lobster seem significant, I am convinced that Parlett’s will be a compellingly intelligent rendition of Cowboy Mouth, and one which I await with baited breath.

Cowboy Mouth plays at the Corpus Playroom at 9.30pm from 13th -17th November