Let's make this the last time we ever have this conversation...

Britain doesn't have enough black theatre, says Phil Tinline. But what can the revival of two plays from the 1950s really do to help?

In 1999 Josette Bushell-Mingo was starring in the West End production of The Lion King when a journalist asked her if she thought the show – a fusion of American schmaltz, African mask and east Asian puppet theatre – was the answer to the lack of black practitioners' involvement in British theatre. Rather than fume at this foolishness, she put together Push 2001, a festival of black British arts at the Young Vic. This week she's back at the same theatre, directing Simply Heavenly, a 1956 musical by the great black American writer Langston Hughes. But how does a show set in Fifties Harlem fit with the Push project?

At first, Bushell-Mingo had her doubts. "I've been aiming to create groundbreaking black British-led work, exploring ballet, digital art, the visual arts, as well as theatre, finding contemporary voices," she says. "Simply Heavenly seemed to be the opposite of this." But then, she says, "I saw that, for the first time, I had an opportunity to create a landscape I'd always dreamed of – where both contemporary work and classic black art could be seen in the same sphere."

Nonetheless, a classic has to have some resonance with life today. So she asked "what Hughes is trying to tell us". Simply Heavenly follows Jess B Semple's comic struggle to do the right thing by his girl, surrounded by other impoverished black Harlemites trying to enjoy the present without upending their precarious futures. Even in this pre-civil rights era, Bushell-Mingo explains, Hughes was criticised for a lack of militancy about Harlem's conditions. "He accepts the backdrop of racism, poverty, ignorance, and doesn't forget the grief and the hardship of it, but he's paying tribute and respect to everyday people." In a world that continues to associate black writing – and people – with "issues", there is still a quiet, useful radicalism to this.

In 1999 the Macpherson report endorsed the concept of "institutional racism" and prompted self-examination by many public institutions, the theatre included. Informal discussions at Nottingham Playhouse became a conference, a report and finally a theatre company, Eclipse, dedicated to tackling a specific problem – the absence of black writing in mid-scale regional theatre. Given these origins, it seems strange that for its first production Eclipse has opted to stage Moon on a Rainbow Shawl, another safe transatlantic play from the mid-Fifties.

For Bushell-Mingo, directing Simply Heavenly seems to be a dance with the past before she creates the next instalment of the future. But where Push is aimed at arts savvy Londoners, Eclipse is concerned with the trickier problems of coaxing regional audiences – black and white – to see black writers' work. For Eclipse's producer Steven Luckie, going back to Trinidadian actor-playwright Errol John's 1957 classic is part of a strategy.

"We needed a starting point," Luckie explains. "Moon is a well-established play that won't alienate the ordinary audience and encourages a new audience, a black audience. It's on syllabuses, it's considered a classic, it's tried and tested." He is fully aware, he says, that the play's post-war Trinidad setting bears only an indirect relationship to contemporary black British life. But he points out that Eclipse has commissioned a new play from Roy Williams, bringing a leading London playwright to mid-scale regional spaces.

In the meantime, though, these two shows offer us a telling glimpse of the lives of the post-war poor in New York and Trinidad. Each opens up a world of cramped housing and public space, where street vendors and musicians are constantly on the make, where the young are aspirational, the old resigned. Paulette Randall, director of Moon, points out that these stories still matter today. Ephraim, a young trolleybus conductor, is so desperate to escape to England he pays a devastating personal price. This could make him unsympathetic, but Randall points out that "it's difficult for those of us not in real poverty to know what desperation can do to you." And as she says, economic migration is not exactly a thing of the past.

There is a big difference, though, between this story from a black Briton's Caribbean past and Simply Heavenly. Bushell-Mingo sees staging an American text in Britain in playful terms. At the first rehearsal, she suggested, with a twinkle in her eye, that the company "enjoy being Britons pretending to be Americans". But Eclipse is addressing the divide directly – Roy Williams's play will explore the tensions of an Anglo-American black relationship. "You can't ignore the great quality of work coming from America, but we need to hear about the black British experience first," Luckie says.

For all their energy, Luckie, Randall and Bushell-Mingo share the hope that this sort of effort is not required forever. Randall, a veteran of many such projects, acknowledges some progress, but expresses weary gratitude that Bushell-Mingo has picked up the baton. Luckie wants to create a legacy that will keep bringing black writers into regional theatre. Bushell-Mingo, meanwhile, expresses the hope that we won't still be having this conversation in a few years' time. Ultimately, all their efforts rely at least in part on white audiences feeling themselves able to identify with black characters – just as black audiences are expected to identify with white characters. Perhaps Moon and Simply Heavenly will encourage this, by pointing up what should always have been obvious: that black people, like everyone else, have a long history of being magnificently ordinary.

'Simply Heavenly': Young Vic, London SE1 (020 7928 6363) previews from Friday, opens 17 March to 12 April. 'Moon on a Rainbow Shawl': Bristol Old Vic (0117 987 7877) from tomorrow, on tour to 12 April