Macabre, provocative, sexually-charged, unrelentingly intense; Northern Ireland Opera’s visceral interpretation of Richard Strauss’s opera Salomewas all these things and more. And few who were present are ever likely to forget the sight of soprano Giselle Allen’s Salome, drenched in John the Baptist’s blood and pleasuring herself, in paroxysms of ecstasy, with his decapitated head. This matinee performance was undoubtedly a stimulating alternative to church and Sunday lunch. As one well-heeled septuagenarian lady commented at the end of this very rock ‘n’ roll show: “I’ve never spent a Sunday afternoon quite like that before.” Nor Allen, as like as not. In…