Classical : Mozart Double Bill Covent Garden Festival, London

Mozart wrote The Impresario at the command of Emperor Joseph II for a double-bill shared with Salieri's Prima la musica e poi le parole. It's froth about two rival prima donnas making life hell for an impresario, and at 35 minutes it's just about bearable as a warm evening's diversion. After the ripping overture, which still features in concert programmes, there's little musical interest, although there are a few very high notes.

Staged in the coolly pompous, neo-Egyptian vastness of the Grand Temple of the Freemasons' Hall in Great Queen Street, the piece was a good vehicle for Judith Howarth, who got a big round of applause just for her entrance in leotards, a huge red and black spotted stole and a few feathers in her hair. She strutted and pouted very provocatively, though Elizabeth Vidal, dressed like a wedding cake, had the highest notes of all, which she screeched out for all she was worth.

Andrew Sharp's production had no sets and took place on a sort of cat- walk, with Paul Goodwin conducting the Academy of Ancient Music on a very high, raked platform at one end. Having to address the large audience on three sides forced the singers to be highly mobile. The spoken part of the Director had John Bernays even climbing into the galleries, announcing, in Sharp's English version, that he had struck a deal for a live broadcast by satellite to over 140 countries - a neat, if unintended mockery of the whole inflated occasion.

Zaide was written some six or seven years earlier, and Mozart completed only 15 numbers - possibly three-quarters of what he had in mind. As an escape story from a harem in the form of a singspiel (with spoken dialogue), it's a pre-run of Die Entfuhrung aus dem Serail, but a lot inferior. Zaide is hopelessly protracted and wooden, and we can be thankful that Mozart wasted no more time on it.

In this co-production, by Opera Theatre Company from Dublin and Musiektheater Transparent from Antwerp, there was even less to look at than in The Impresario, and the lovers, Zaide and Gomatz, were taken by two young singers, Anne Cambier and Iain Paton, who were rather too unformed vocally to redeem their uninspired music. Russell Smythe, as the warm-hearted prison guard, brought a welcome touch of maturity. It's hard to believe that Mozart, at about 23, wrote such a flat aria as Zaide's opening "Ruhe sanft, mein holdes Leben".

More interesting, simply because they're not paralleled in any of Mozart's well-known operas, are the melodramas, or scenes in which a character declaims over continuous orchestral music, which could quite well stand on its own; the trouble is, they don't advance the drama, nor offer any of the vocal interest of an aria.

To have an interval just after the guard decided to help the lovers escape, seemed an unnecessary way of protracting this not very gripping adventure, though perhaps it was convenient for the caterers involved in the reception. The list of sponsors and organisations that contributed to the evening would fill another column. Perhaps it didn't matter much what the music was like - this was really a social event in a spectacular and intriguing building, and the main drama of the evening was chasing, or escaping, other members of the audience in the huge corridors and lobbies, and testing the sturdy plumbing in the period lavatories.