Operettas are not supposed to have plausible plots, yet the seemingly implausible plot of Franz Léhar’s Merry Widow cuts to the quick in the current environment of possible sovereign bankruptcy. A “merry” widow would be rather callous in any case. The saccharine-soaked melodies, however, are enough to keep me still. Long an admirer of the Gold and Silver waltz, I am biased.

The widow in question, Hanna Glawari, has inherited her husband’s fortune, which is large enough to save her native Grand Duchy of Pontevedro from bankruptcy. She is visiting Paris, searching perhaps for her next husband.

The Pontevedrian ambassador to Paris, Baron Zeta, needs to prevent Hanna from accidentally marrying a foreigner, so that her inheritance remains in Pontevedro. He encourages the embassy Chargé d’Affaires, Count Danilo Danilovitch, to win Hanna’s heart. Danilo jilted Hanna years ago by order of his uncle on account of her poverty, and now refuses to admit he still loves her, for fear he might be suspected of being after her money. In the meantime, Zeta’s wife, Valencienne, a former chorus girl, makes a valiant attempt to break off an affair with a dandy, Camille de Rosillon.

This unlikely plot of amorous adventure unravels in one long party that moves from the embassy ballroom to the garden at Hanna’s house, decorated as Maxim’s nightclub in the third act. The energy of the cast in the latest Opera Australia production is infectious. Director Giles Havergal moves the uninterrupted revelry along in a crisp and rapid but not breathless pace.

The English libretto by composer and scriptwriter Kit Hesketh-Harvey is no mere translation but a true adaptation. The language is light and mischievous. The rhyming verses are appropriately sentimental with occasional clichés that endear rather than alienate. “I’m heading to Maxim’s,” Danilo says, “the house of broken dreams…”

Amelia Ferrugia as Hanna and David Hobson as Danilo hog the show. Ms Ferrugia’s warm, velvety tone, fluid coloratura and effortless projection would make her a worthy successor to Dame Joan Sutherland in the same work several decades ago.

The real surprise is David Hobson, whose delicate voice glibly weaves its way around the highest notes without exertion and brings sympathy to the role of Danilo – a voice that combines the best of Michael Crawford and Charles Aznavour.

Henry Choo’s naturally comic look as Camille is loveable, bringing full-bodied lyricism that resonates throughout the auditorium, although Sian Pendry’s Valencienne clearly has the upper hand. John Bolton Wood as Baron Zeta is every inch the diplomatic buffoon.

This Opera Australia production is by no means lavish. The set is sparse, made up mainly of moveable statues of naked women holding up lamps. Chandeliers painted on drapes that rise and fall throughout the evening look a little down market. Dashing uniforms, finely laced ball gowns and colourful ethnic costumes, though, save the day.

The orchestra, under the direction of Andrew Greene, is decorous in articulating Léhar’s sumptuous orchestration, allowing the splendid melodies to shine without being overwhelming. Even the violin solos are but glittering embellishments.

A cast determined to have fun, wallowing in schmaltzy melodies that refuse to go away, fine singing, spirited cancan, and a dash of cabaret make for an evening of superb entertainment.

Léhar’s masterpiece is no stranger to Australian audiences, having debuted, according to the programme notes, in Melbourne’s Her Majesty’s Theatre three years after its premiere in Vienna. The latest offer by Opera Australia is a credible extension to the country’s tradition in presenting this delightful work.