A black woman who bears a disconcerting resemblance to Nina Simone is having what we would now call a detox. No booze, fags or phone, just her, an imaginary piano and a handy suitcase full of props from her life. Via a conversation with her father, Apphia Campbell telescopes the pianist-singer-civil rights activist's career into an intense hour of character, exposition and highlights from the Simone song book.

It is a tribute to the strength of her performance that, despite the whirring air con, sub student theatre set and Poundland musical budget, this show glows. As the pace picks up and Campbell transforms from a little girl determined to be the first black classical pianist to the political firebrand who plays the devil's music with the black power movement's lyrics, it gets better and better. But a real piano, surely the heart of Simone’s story and as important in her personal struggle for racial equality as Martin Luther King, was sorely missed.

If only the team behind Janis Joplin: Full Tilt could be unleashed on this material, it would make the perfect companion piece. As it is, it overcomes the odds to be extremely good.

(Gilded Balloon, 0131 622 6552, until Aug 25 (not 13), £9.50 (£8.50).