REVIEWS : Opera Crystal Balls / Stephen Edwards Lilian Baylis Theatre, London

As Elizabeth I's court astrologer, John Dee no doubt had a sneak preview of his own life story as told in Crystal Balls. Even so, it's unlikely he got all the jokes. "It's as good as cooking haddock/ With a singing Fanny Craddock," the Doctor intones in Act I, brewing up base metals into gold with his fellow magus Edward Kelly.

Similar couplets abound in Compact Opera's new slice-of-Elizabethan-life production, but rarely just for fun. Out of the spicy jingles of Justin Fleming's libretto, real characters emerge in the crucible of verbal invention. There's also a story with a sharp twist and searching theme: knowledge is fine, but it's not much good without wisdom.

Dee himself is an upright man who needs the blackness of Kelly to light the way to his own self-awareness. While Kelly craves gold, Dee's alchemy is symbolic, knowledge his agent, and soul the thing to be transformed. Yet he lacks wisdom. In his wish to believe, he believes anything.

A quest for angels sums up his idealism, through which Kelly controls him. Losing Elizabeth I's affection through loyalty to his wife, Dee flees with his colleague to Prague and the court of Rudolf II. Here, through angelic "messages", Kelly dupes Dee into wild group sex. Elizabeth tricks him into returning and brings about Kelly's fall, but her warmth has now turned to ridicule. Dee's humiliation is complete. Transmuted, he accepts his wife's love. But can a fool be raised from his folly?

A strong cast takes credit for making this a resonant question rather than a problem of dramatic credibility. John Hancorn's Dee paints a troubled mind with his soft yet forceful baritone. Darron Moore's Kelly matches a darker voice with his elfish, daring looks. Like mezzo Janet Mooney, soprano Adey Grummet takes four roles, nicely contrasting a chaste Queen Elizabeth with a lusty Jenny Kelly. Mooney's loving, puzzled, redeeming Mrs Dee has a touching simplicity.

Without breaking new ground, Stephen Edwards's score, played from keyboards by Simon Kent, offers music of unflagging energy for all occasions. Broadway- tinged ensembles are particularly strong, lending operatic depth to a plain stage of backdrop, pentacle and alchemist's bench with piled up books for chairs.

But above all, it's the words that count. Fleming's taste for the music of alchemical terms and eccentric phrases is infectious. Rudolf's museum of curios contains an homunculus pickled in pink gin and the scrotum of Pythagoras. It takes balls to rhyme such lines.

n Last performance tonight. Booking: 0171-713 6000