It doesn't do to take Così too seriously. Like many another opera (think Turandot: Calàf is quite happy to have Liù be tortured and then die for him), its plot doesn't bare close scrutiny. Yes, Dorabella and Fiordiligi are proved to be faithless (like all women, the title tells us: not something that goes down well in these politically correct times), but Ferrando and Gugliemo hardly come out of it all smelling of roses.
The only way a modern audience is going to accept it (if, in fact, they think about the plot at all!) is if it is played as Pimlico play it, as comedy. This production is, in the words Jane Austen used to describe Pride and Prejudice, "light and bright and sparkling". True, the serious ending doesn't quite fit but the fun and the glorious music relegate that to comparative unimportance.
And it is a good production musically. The small orchestra (eight instruments and continuo) support the singers well, and the singers themselves are good. Regrettably for them, opera singers don't get many chances to perform, except perhaps on the concert stage, so it is hardly surprising that singers of a very high quality are happy to tour in small-scale productions of this nature: for us, however, this is, in many ways, a good thing, for it means that we can enjoy productions of this standard even at 400-seater venues like the Customs House - and at a reasonable ticket price!
Director Ptolemy Christie brings a real sense of fun to the piece with comedy that ranges from borderline-splapstick to the subtle, and the cast throw themselves into it with obvious enjoyment. But this doesn't mean that the music suffers. Far from it: the famous arias - Ah, guarda sorella, for example, and Soave sia il vento - were beautifully sung and this high standard was maintained throughout.
The tour continues: see them if they come near you!