‘Romance, Revenge, Heartbreak, Hope’ states the poster for the Wales Millennium Centre’s latest new musical Tiger Bay which is being produced in association with Cape Town Opera where it enjoyed a try-out run in March. With a script written by South African author Michael Williams (whose mother was born in Cardiff) and a musical score written by local composer Daf James, Tiger Bay is a historical tale about Cardiff’s heritage and how events of the 1900s shaped the Cardiff Bay of today.

It’s a bold production for the Wales Millennium Centre and elements of the original story are based on factual events. This is a story about a melting pot of a culturally diverse community without the usual racial, religious and class distinctions. Cardiff Docks was the main source of coal for much of the industrialised world and there is social tension and a risk of riots and strikes.

At the second preview performance tonight, Tiger Bay looks in remarkably good shape for a musical that will enjoy a short, two-week run in the area where it is set. The first half is a real song-fest with a series of large-scale company numbers with multiple parts and complex harmonies. The downside to this is that it is more difficult to engage with individual characters as the storyline gets rather tangled up in the staging.

The second half is much stronger as more traditional 'book' scenes are used, with two or three characters on stage dealing with a situation – it's much easier to empathise with the characters and care for their plight.

The plot features a variety of main characters from different backgrounds. The rich 3rd Marquis of Bute (John Owen-Jones) is a spiritualist who tries to contact his dead wife and find his son. Is the exotically-named clairvoyant Leonora Piper (Liz May Brice) able to help him, and what connection does the Marquis have to Ianto, one of the water boys who helps the carters move their wagons along the tracks? And what is Ianto’s true identity?

The Marquis’ right-hand man Seamus O’Rourke (Noel Sullivan) asks young shop girl Rowena Pryddy (Vicki Bebb) to marry him, but how will local girl of the night Klondike Ellie (Busisiwe Ngejane) feel about this and what is the nature of his relationship with her?

There are strong echoes of Les Miserables throughout, with a touch of Oliver! in the water boys’ scenes and even a hint of Ragtime. Daf James’ score features a range of musical styles – from a Welsh language hymn to a Dreamgirls rock moment and an African folk song – reflecting the diversity in Tiger Bay at that time. There are some nicely-played supporting characters too, including Suzanne Packer’s landlady Marisha who offers a ‘Brains dark’ (a local beer available in the bar) to those who frequent her boarding house, and Rhidian Marc in two contrasting roles.

Local shop David Morgan – a well-remembered but now long-gone local department store that was once at the centre of the Cardiff shopping experience – is featured in several scenes that evoke shop life years ago. Vicki Bebb as Rowena enjoys several fun scenes with the other shop girls and carries much of the plot in the second half and has some tender scenes with Dom Hartley-Harris – she’s a real presence and definitely a name to watch.

At just over three hours, the show is too long and needs to shave half an hour off its running time by losing some of the numbers, re-focussing the story and revising some overly-stylized choreography in order to reach the next level of its development. But directors Melly Still and Max Barton stage the show well and use the vast auditorium of the Wales Millennium Centre effectively in the protest scenes. This tale of people putting aside their differences and working together tries to draw comparisons with the political and social landscape of today. It’s still a work in progress but the show ends on an emotional note and deserves a life outside of Cardiff Bay.