"Thank you, Walperinga!" is not the most auspicious of rock-star cries at the end of a set, but, hey, it's a small town and a gig's a gig.

It's a cry uttered by Dan (J.R. Reyne), the rocking frontman of Cardiac Arrest, but the real star of this show is Jessica Mauboy as his bandmate Billie.

It's all about the Mauboy. The Secret Daughter is a show written for her and pretty much amounts to a showcase for her immense acting and singing talents (accompanying album out now, but of course). Billie is a country girl from a small mining village, facing a mostly uninspiring future as a part-time baker/pub singer. She's a bright woman with a strong set of principles, and is endlessly unflappable in dealing with the mishaps of her father Gus (David Field), a hapless magnet for trouble.

Except that he's not her father. A chance meeting with Jack Norton (Colin Friels), a wealthy Sydney hotelier, leads to the revelation that he's actually her dad, a fact confirmed after his untimely death in a helicopter crash.

The main thrust of the story is a fish-out-of-water tale as country girl Billie adjusts to a new set of fancy relatives in the big smoke, welcomed into the fold with varying degrees of enthusiasm – and a big question mark over her inclusion in Norton's will.

No stranger to belting out a tune or two, Mauboy is given multiple opportunities to show off her vocal skills in each episode. While sometimes the engineering of opportunities for songs is clunkily contrived and hamfisted, the pay-off is always that powerful voice.

She tackles a mix of contemporary and classic tunes, from Cold Chisel's Flame Trees, Rihanna's Diamonds and Bruno Mars' Just the Way You Are. Her version of Crowded House's Better Be Home Soon could melt steel girders – admittedly it's a song with such a beautiful, affecting melody you'd be hard-pressed to stuff it up, but Mauboy is so immersed in all of the songs it's as if she herself has lived through the stories told in them.

And that's the core factor behind the beauty of this show: Mauboy's authenticity. As an actress she is effortless, natural – it is hard to distinguish where Mauboy ends and Billie begins.

In fact, it seems so little of a stretch for her, one wonders whether the material is enough of a challenge. Where The Secret Daughter falls short is in its soapy elements. A lot of the dialogue is jarring in its approach and lacks a realistic touch. Also the narrative works so hard to push forward all the plot machinations, it barely gives the actors breathing space.

The background players fill out proceedings with mixed success. A standout is the vibrant Home and Away's Bonnie Sveen as Billie's spunky mate, Layla. Field is also a fantastic addition, his baritone grumble a source of much of the show's gentle comedy and hangdog expression brilliantly conveying a man who hates that he screws up so monumentally but can't help himself.

Billie fights to keep her integrity as she faces suspicion, pay-off offers and questions over Norton's will. Money can't buy integrity, and she battles to stand her ground amid targeting by Norton's snotty, money-grabbing widow Susan (Rachel Gordon), who sneers at country folk.

Billie is someone trying to find her place in the world. Jessica Mauboy's place is rightly fronting Australian dramas and it's with deep anticipation that we wait to see what else she will have ahead.