L'Amour Masque, Festival Theatre, Edinburgh

French operetta is different from Viennese. It is heartless, witty, uninvolving, smart as hell. It would be easy to say that it travels badly, if it were not for the unending popularity in Britain of Offenbach's masterpieces. But L'Amour Masqué is a turkey. It is trite, vapid, and as sexy as a wet afternoon in East Kilbride.

Sacha Guitry's libretto is about a girl who falls in love with a photograph of a young man, only to find out it was taken 20 years before. She also has two other lovers, which was, apparently, shocking in 1923. The text is written in heroic couplets - including all the dialogue - like Molière, which sounds funny in French but is untranslatable.

Messager's tunes are ingenious rather than haunting. You hear the man spinning out notes, trying harmonic effects, in a sterile desire to bring it to life. At one point he quotes Bizet. The rest is an anonymous mixture of everybody else.

This operetta is a curiosity, worth reviving only as a historical document. It defeated even the distinguished director Bernard Pisani. He choreographed every movement, even in the solo numbers, making much of the various dances - tangos were evidently the rage at that time. But the singers of the Opéra de Tours had not mastered it. They hesitated and wobbled. Only Pisani himself, in the role of Baron Agnot, had really got inside it.

Some of the singers had reasonable operatic credentials. But on this showing, there were no real voices, apart from the tiny lyric tenor of Franck Cassard as the Interpreter. In the leading female part (she has no name), Sophie Haudebourg lacked the vocal weight or sense of style needed to make the romantic numbers rise above mediocrity. The two maids, sung by Sophie Hervé and Lydia Mayo, were neither musically pleasing nor strongly characterised.

The odd thing was that the most French, the most sophisticated element was the orchestra. The Northern Sinfonia are, however, English. They were directed by Jean-Yves Ossonce, who has made quite a thing out of reviving Messager works at Tours. In spite of this, the cast seemed often to ignore him.