The Full Monteverdi, Daffodil Restaurant, Cheltenham

Music theatre hardly comes more visceral than this, short of the actual physical involvement of the audience. In the elegant Art Deco setting, you are just finishing your smoked halibut and eyeing the waiters expectantly when the man at the next table suddenly starts a scene with his frail, mildly distraught-looking companion.

Music theatre hardly comes more visceral than this, short of the actual physical involvement of the audience. In the elegant Art Deco setting, you are just finishing your smoked halibut and eyeing the waiters expectantly when the man at the next table suddenly starts a scene with his frail, mildly distraught-looking companion. But he isn't talking, much less shouting. He is singing, and the music is Monteverdi's "Ah dolente partita," from the fourth book of madrigals. "Oh wretched parting!/ Can I leave you without dying?"

Should one intervene? Then several other couples start up (after all, it's a five-part madrigal). For an hour they torment themselves and each other; they sigh and moan, they rage and emote, they kiss and make up; but it's no good. In the end the companions, unable to get a word in edgeways, flounce out one by one, leaving the scene-makers to lament alone. At last the waiters arrive with the pollo alla diavola.

All this is John La Bouchardière's idea of a staged production of a set of late sixteenth century unaccompanied madrigals, using the group I Fagiolini (The French Beans) as his porcellini d'India (guinea pigs). It's one of those bright ideas that might be a complete nightmare in practice: Tafelmusik in a hopelessly wrong sense.

Unexpectedly it succeeds; cleverly, amusingly, above all musically. Anyone who has ever sung Monteverdi madrigals knows the difficulties of coordination they present, because of the very free rhythmic expression. To sing them without copies in a kind of mad antiphony, with the group dispersed round a largish restaurant, leered at by fellow diners, who may try to catch your eye and will certainly be listening out for the trivial defects that are usually masked by distance, is to invite disaster.

In the event nothing came unstuck. I caught my neighbour out in one early entry, quickly disguised, in the whole fourth book - and he was two feet away from me. Admittedly the singing was not primly immaculate in the English concert style, where the heart splits without a flicker of vibrato. It was vibrant and Italianate, but without the horrors of intonation that sometimes go with the genre. Miraculously, some kind of musicianly balance was maintained, though this must have been a virtual quality, a trick of space. The same applies to the effect of blend, which only goes to show how relative such values are. Under Robert Hollingworth's incredibly discreet direction, everything went like smooth, passionate, clockwork.