For Rigoletto, the director, Tim Coleman, and the designer, Lez Brotherston, have created a world that evokes not so much a 16th-century Mantuan court as a late 19th-century brothel (for the opening of Act 1) and a steamy military locker-room (for Act 2).
There was throughout an uneasy balance between send-up and the more earnestly felt emotional protestations of Rigoletto and his daughter. The first physical encounter between Gilda and the Duke, for instance, reeked heavily of parody - of both operatic embrace and operatic farewell.
In the pit, however, Kenneth Montgomery was having none of it. His pliant conducting of the Ulster Orchestra was emotionally true, and rich in imaginatively balanced textures, lit with unusual finesse and cunning.
As Gilda, Susannah Waters made a perfectly sweet caged canary, though one that was more vocally refined than affecting. Peter Riberi as the Duke offered just the sort of tenoring one would expect to go with the character's crude sexual posturing and opportunism. Kimm Julian's Rigoletto fluctuated vocally, mirroring his journey from confident jester to bereaved father. Also striking were the indignant Monterone of Paul Nemeer and the rich-toned Sparafucile of Alan Ewing.
The linchpin of the 1989 Faust was the Mephistopheles of French bass-baritone Frederic Vassar, a spry character who gave the impression of marshalling those around him like a charmingly decadent master of ceremonies.
The current revival, using the original director/designer team of Bliss Hebert and Allen Charles Klein, again follows the Oeser edition, with spoken dialogue rather than recitative, and without either ballet or 'Soldiers' Chorus'.
The appealing, pantomime- style raciness that centred on Vassar has now, sadly, been lost. The new Mephistopheles, Claude Corbeil, is short on animation, wit and good humour, and lacks the slightest taint of devilishness.
He is the soul of liveliness, however, by comparison with the listless Faust of his fellow Canadian, Guy Belanger. His Act 1 transformation from world-weary scholar to youthful libertine must be gauged a total failure, as he doesn't even manage to show the slightest hint of amatory interest in the brightest feature of the evening, the Marguerite of Maureen O'Flynn.
The American-born Ms O'Flynn was vocally secure and musically sound, though more impressive in the plaintive expression of loss in Act 3 than in her rather too tightly reined response to the gift of jewels in Act 2.
The members of ONI's amateur chorus, seated in serried rows at the back of the stage, were in poor vocal form (as in Rigoletto). And even the playing of the Ulster Orchestra under Stephen Barlow didn't recapture the freshness one remembers from when this production was new.
Faust: tonight, Fri. Rigoletto: Thu, Sat. Box office: 0232 241919.
Michael Dervan is music critic of the 'Irish Times'.