If Waterford is famous for crystal, Wexford is renowned for opera. Sadly, Waterford Crystal was a victim of the recession but, along Ireland’s south-east coast, Wexford Festival Opera continues to trade, dealing in operatic rarities. Each year three operas are presented in Ireland’s National Opera House and the chances are that they will be unfamiliar – even to the aficionados who descend upon the town like hungry seagulls on the quayside. The only La bohème you’d find here would be Leoncavallo’s. This year’s festival opened with Frederick DeliusKoanga – a tricky piece to get right, but director Michael Gielata largely succeeded.

Koanga owes much to Delius’ experiences in America. Sent to Florida at the age of 22 to manage an orange plantation in Solano Grove, he paid little attention to growing oranges, but more to music. Koanga, one of the first serious operas to feature black protagonists, draws on the influences of spirituals and African-American music, nearly forty years before Gershwin’s Porgy and Bess.

A framing device has Uncle Joe tell the story of Koanga, an African prince sold into slavery. Martinez, the Louisiana plantation owner, realises Koanga will not be bullied into submission and hatches a plan to use Palmyra, his wife’s maid (and secret half-sister) to persuade him to become submissive. It works and Martinez suggests Koanga and Palmyra marry, much to the fury of estate manager Simon Perez, who has been making unwanted advances towards Palmyra. At the wedding, Perez abducts Palmyra. Koanga escapes and places a voodoo curse on Martinez’s estate. In a state of collapse, the plantation struggles on. Perez offers to save Palmyra. Koanga returns to rescue her, but is captured and killed. Palmyra renounces her Christian faith and stabs herself.

The ‘squirm potential’ in Koanga is high, with a white composer appropriating – or imitating – black man’s music, plus the awkwardness of Act III’s Voodoo bloodletting ceremony. The libretto is clunky. However, Gielata handled his staging sensitively. James Macnamara’s white box set pulled open and allowed projections to set the scene. Through opens panels at the rear, the plantation’s corn grows as high as an elephant’s eye and dense greenery serves for a swamp, atmospherically lit by Ian Sommerville. African art was referenced, Koanga making an impressive entrance before a blue-bead mosaic. Some of the choral blocking was clumsy. The Chorus sang lustily, especially in the Creole songs of Act II, but Delius has the opening chorus sung off-stage. Having them on-stage helps with co-ordination, but meant that chorus and banjo players were shunted on and off too much, distracting the eye. The pursuit and capture of Koanga is weak, taking place off-stage – Delius’ fault – which Palmyra narrates.

Conductor Stephen Barlow pushed the score on apace. Delius proclaimed “I want to tread in Wagner’s footsteps” and, although there are no leifmotifs, Koanga is highly chromatic, through-composed and contains long symphonic interludes, none more luscious than the string lines leading into the dawn epilogue, so beautifully played here that I didn’t want the chorus to break the spell. Nothing could be done to dispel the notion that Delius’ ensemble writing isn’t really that convincing, the Act I quintet giving little opportunity for characters to develop strong vocal lines.

“Soft as the sound of silver torrents playing on the rocks” is how Koanga describes Palmyra’s voice and that’s a pretty accurate assessment of the qualities displayed by South African soprano Nozuko Teto. She has a glorious, full lyric soprano which gleams throughout its range. Her Act II arioso “The hour is near, when I to him my soul surrender” was powerfully delivered, her diction crystal clear. Teto carried off the score’s only famous number – La Calinda – neatly, toasting her bridegroom before dancing for him.

Quiet dignity and a powerful presence marked Norman Garrett’s Koanga. Vocally, however, he is a size too small for a role which requires his baritone to roar with greater authority when placing his curse. Koanga prays to Voodoo “Let thy thunder wake applause”; Garrett simply needed more thunder. Aubrey Allicock had a much stronger bass-baritone, though was little used in the dual roles of Uncle Joe and the holy priest Rangwan. Jeff Gwaltney had plenty of Puccinian ‘ping’ – and some odd vowel sounds – as Simon Perez, making a strong impression. Christopher Robertson’s Martinez was under-projected, though Kate Allen made the most of her role as his wife, Clotilda.

There’s no doubting that Koanga is a flawed work, but this production presents its case for the occasional outing. Nozuko Teto, however, needs far more than an occasional outing. Let’s hope some casting agents were afoot among the Wexford audience.