Little of the urgency or foul chill that grips Verdi's Macbeth is possible without an orchestra. Verdi, in fact, telegraphs everything you need to know emotionally in the brief orchestral prelude, before anyone sings a murderous note.

Which is one reason why the version of this opera imported by FringeArts and Opera Philadelphia this past weekend could only ever be a partial success. The prelude isn't played at all, Verdi's music has been shifted around and adapted (in some places cleverly) by Fabrizio Cassol, and a small instrumental ensemble is placed on stage and asked to carry the load of an entire orchestra.

As a piece of music, it doesn't quite work. There's great resonance between the recent genre-jostling artistic direction of Opera Philadelphia and Third World Bunfight, the South African performance troupe whose artistic director, Brett Bailey, realized this Macbeth. But if it's opera you came listening for this past weekend at the Prince Theater, you may not have found it.

It turns out that the story makes a beautiful transition from something traditional and more Shakespearian to post-colonial Congo, where money-grubbing warlords mow through body counts without conscience, and projected images bring the audience into today with a grisly documentary-realism. Humanity has progressed not at all, this updating declares. When Macbeth hears his fate from the witches and concludes with a two-word vulgarity that the future looks grim, he might as well be speaking for us all.

But the singing, in Italian, is uneven, and the production lays it on thick in places. At Saturday night's performance, conducted by Premil Petrovic, Nobulumko Mngxekeza as Lady Macbeth didn't have a voice that could do it all, but it had a lot: a variety of timbres over an incredible range, and at time a soaking emotionalism. Owen Metsileng had his moments as Macbeth, particularly in quieter stretches when instead of straining he could explore, vocally, the finer points of what it means to have your grip on reality slipping away.

The chorus was strong, and particularly poignant in the quiet way they drew down the emotional arc at the end. Cassol delegated instruments in inventive ways, even absent real orchestral impact, by combining percussion with others – the creepy, silken hybrid of vibraphone and low flute, for instance. Thankfully, he avoided Hollywood jungle clichés.

Less might have been more on the production side. The creators of this 90-minute, intermission-less piece worked hard to head off audience indifference at the pass. The appearance of a disco ball in one of Lady Macbeth's arias was at odds with the mood of what she was actually singing about, as was a karaoke devise too glib at another turn. Sometimes you have to just have to stay out of the way and trust your audience to groove to the moment Shakespeare and Verdi meet across the centuries to agree on what an awful thing is man.