Lenin's embalmed corpse is the strangest of inspirations for a piece of music theatre. But Giorgio Battistelli's The Embalmer, which premiered last night at the Almeida King's Cross, dramatises the ghoulish mechanics of Lenin's mummification, as seen through the eyes of Dr Alexei Miscin.

The piece was designed for Ian McDiarmid, the Almeida's outgoing artistic director, and is a staged melodrama for actor, ensemble (conducted by David Parry) and electronic sounds (conceived by Alvise Vidolin).

Set in present day Moscow, the piece uses Lenin's cadaver as a symbol of the evils of the Soviet regime. But Renzo Rosso's libretto does more than illuminate the communist divisions between dictatorship and proletariat.

Miscin is no innocent everyman: McDiarmid paints a portrait of a sexual obsessive, whose wife has thrown him out, and who drinks himself into a stupor during the embalming procedure. His performance is outstanding, and his energy and intensity make Miscin a grotesque, tragi-comic figure.

But he also captures the political and emotional ambiguities of the role. As the monologue develops, the dead Lenin embodies not just the decay of communism, but also the putrefaction of the contemporary free market. Miscin's most impassioned outbursts are reserved not for Lenin, Stalin, or any of the other "dickhead dictators", but for Russia's botched version of capitalism: "There are gallons of coke, but no bucks, and hundreds of whores, but no fucks."

But there are glimpses of sympathy as well as vitriol in McDiarmid's performance. The most affecting moment - set to Battistelli's most effective music - comes as Miscin relates the torture and murder of his father and his mother's disappearance.

Yet even McDiarmid's mesmerising presence cannot disguise the serious problems at the heart of The Embalmer. Melodrama has always been the most difficult of musical and dramatic forms to get right, and Battistelli's score does not solve the problems. His music provides an expressionist underscore to the whole 90 minute show. But instead of enhancing the drama, the score deadens the pace of the performance. The music cannot react quickly enough to the events on stage. Only in the coup de théatre of the ending does Battistelli's music mesh with the dramatic action.

There is no doubt that McDiarmid's portrayal of Miscin is a fitting performance to celebrate his 12 years in charge of the Almeida Theatre Company. But as a whole, The Embalmer is an unsuccessful stitching of music with words.

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