The Last Five Years is a strange piece of musical theatre that could be accused of gimmickry. There's a little messing around with time as up-and-coming writer Jamie (Fraser Findlay) and aspiring performer Cathy (Vanessa de Jager) meet, fall in love, marry and part. Jamie lives the birth and death of their relationship forwards whereas Cathy starts with the breakup and goes backwards to the beginning.

That means they hit the stage of happy togetherness just before interval. Further, the whole rather bleak story is told in a series of songs. There is no dialogue.

So it probably succeeds best as a vehicle to showcase the work of the performers. Findlay and de Jager both have the necessary energy, punch and flexibility for the style of the show and the songs. Findlay's Jamie is packed with an ambition that will see him succeed as a writer and fail as a husband. De Jager's Cathy is a sensitively done sketch of someone struggling to stay confident in love as her career sloshes along in the shallows of dispiriting auditions and out-of-town productions.

While they could use a little more chemistry as a couple, the piece is so busy giving them songs to sing that there's hardly time. Jamie slides into adultery with a shadowy woman who is clearly not Cathy, a brief presence provided by Rachel Thornton. It's a bit of an awkward device but Findlay is able to use it well to support Jamie's awareness of his drift away from Cathy as his career soars.

Findlay properly plays him as a self-absorbed cad with occasional flashes of sentimental sensitivity like that in The Schmuel Song, a story about a tailor who manages to turn back time that he tells partly to encourage Cathy not to give up.

De Jager's Cathy is more likeable but more vulnerable than Jamie. She is especially touching and deft in Climbing Uphill, a number that mixes the realities of Cathy's emotional hopes with the need to keep cheerfully taking knockbacks in auditions.

Simple "black box" settings have generally worked best in Teatro Vivaldi's visually rich theatre restaurant space. The box set here seems unnecessarily cluttered with props like desk and dressing table accoutrements and a set of golf clubs in a corner that do not appear to earn their keep. There needs to be a little more awareness, too, of sightlines in a crowded theatre restaurant.

However, the stage is certainly in the right place and the tucking of conductor Damien Slingsby's small but supportive orchestra around the corner in the side room works very well.

Intriguingly, in the second week of performances the main roles will be taken by Josie Dunham and Mathew Chardon O'Dea. It might be worth a second visit for those interested in seeing how a change of casting might affect a piece. And it reinforces the feeling that The Last Five Years is best regarded as a musical that exists to reveal what such pairings of experienced performers can do with it.