Only an incurable sourpuss could take exception to Cape Town Opera's production of Gershwin's Porgy and Bess, now on a short visit to the UK.

Its weaknesses, particularly in the second half, are really those of the opera itself, with its stuttering dramatic flow.

We should be grateful for a version in which the black characters are played by black performers, a rarity in most opera companies, which cannot cast the work without importing singers wholesale.

Director Christine Crouse takes the initiative in scenically updating thirty years from Charleston, USA, to 1950s Soweto, if only to point out that there's little difference in a work about poverty and dislocation and the violence they breed.

Hers is a very physical, almost balletic, production of sometimes tribal intensity and the solo singing, with American soprano Lisa Daltirus as a feisty and heartily-sung Bess on the opening night, is marred only by some less-than-clear diction in episodes that take the action forward.

Crouse is pitiless with the crippled Porgy, whom she requires to perform on his knees, mostly while propelling himself by means of a wheelie board. If the heroic Xolela Sixaba was pitching his voice erratically towards the end, he could have been forgiven.

All the great tunes were sung well, particularly Summertime by Pretty Yende as Clara, and My Man's Gone Now by Arline Jaftha as Serena. The exchanges between Crown (Ntobeko Rwanqa) and Bess were electric. Victor Ryan Robertson was a mobile if low-key Sportin’ Life.

Porgy’s ‘promised land’ scene at the end found the whole cast raising clenched fists. In Soweto, it would have been their dream as well.