Ol’ Man River wends its way to Dublin

It's a tale of razzle-dazzle and racism; corsets, comedy turns and cotton bales. Show Boat, one of the first American musicals ever written, has always been capable of touching nerves, and in the hands of the Cape Town Opera, this production never lets the political message at its heart be drowned out by frivolity or feather boas.

When the show docks in Dublin's Bord Gáis Energy Theatre for a five-night run from July 29th, it does so fresh from five-star UK press reviews. On opening night in Manchester, Otto Maidi's rendition of its stirring signature song, Ol' Man River, received mid-show applause at a volume that audiences usually reserved for the curtain call. The show's second most-famous song, Can't Help Lovin' Dat Man, meanwhile, could be heard during the interval being cheerfully trilled in the ladies' loo.

Composed by Jerome Kern with a book by Oscar Hammerstein II, Show Boat is set between the 1880s and the 1920s, with the action shifting from the Deep South to Chicago in its second, flapper-filled act. The members of the Cape Town Opera company, however, have infused this story with the more recent memory of their own painful experiences.

"It relates to where I come from, my history as a black South African," says Maidi, who plays Joe, the African-American dock worker on board the Cotton Blossom, the Mississippi show boat of the title. Every time he sings Ol' Man River, it becomes new, he says. "I feel it myself. I sing it for myself. There is so much emotion in it. The people who understand – the older audience – I think it reminds them of so many wrong things that have happened."

The musical is "absolutely relevant" to today, agrees Lynelle Kenned, who plays the Cotton Blossom's leading lady, Julie. "As recently as 20 years ago, a lot of us were still experiencing these things back home. It is not that far-fetched. If you have not experienced it, if you are too young to have experienced apartheid, just ask your parents, just ask your grandparents."

Show Boat, alongside George Gershwin's Porgy and Bess, is the most relevant political musical for South Africa, director Janice Honeyman believes. "I thought that we could do it with a richness that maybe another company couldn't do," she says. She cites her treatment of the song Mis'Ry's Comin' Round, sung by Joe's wife Queenie, which serves as a portent of the trouble that is about to befall Julie.

"Mis'Ry is a number where it's almost, if I could think of an American equivalent, it would be slightly voodoo. But we've got it with the South African feeling of communing with the ancestors. A lot of companies who do it cut that number, but for me, it's the whole core of a different culture at work – a culture that is in contrast to the white culture that we see."

While there have been many stage revivals and film productions of Show Boat since its Broadway premiere in December 1927, there has also been much caution surrounding its staging, for reasons that have come full circle over the decades. When Kern and Hammerstein took the surprise decision to adapt Edna Ferber's 1926 novel of the same name into a musical, they touted it around to various producers. "All of them sensed the politics in it and said, 'it's not quite right for us'," Honeyman says.

It eventually fell to producer Florenz Ziegfeld, best known for glitzy, chorus-girl variety shows known as the Ziegfeld Follies, to stage Show Boat's rather less breezy mix of plots: alcoholism, gambling, marital discord and, most significantly, the laws against miscegenation, or inter-racial marriage and relationships. The misery forewarned by Queenie arrives when a local sheriff attempts to arrest Julie for being a "mulatto" (mixed-race) woman who, in "passing" for white, has broken the law by marrying a white man, Steve. Julie and Steve are forced to leave their positions as the star performers on the show boat and Julie, abandoned by Steve, descends into alcoholism and, indeed, misery.

Ziegfeld recognised the brilliance of Show Boat but was wary of it, taking a dislike to its two "heaviest" numbers. Mis'Ry's Comin' Round was cut from the original production, but he need not have worried about Ol' Man River: It was a hit. The song's slow-tempo, bass-baritone vocal takes the harsh, endless flow of the Mississippi as a metaphor for white men's indifference.

A clip of the 1936 film performance of the song by African-American star Paul Robeson, who Kern and Hammerstein had always intended to perform the song, is the kind of haunting wonder for which YouTube was invented.

In 2011, Time magazine named Ol' Man River among the 100 greatest English-language recordings in history. Certainly, some 87 years since Show Boat broke ground on Broadway – partly because it featured an integrated cast – the song retains an unusual level of potency. It is musically rousing, yet lyrically full of despair. The river "just keeps rollin' along", no matter how much the workers on the Cotton Blossom might suffer.

Subsequent productions reinstated Mis'Ry and other material, but lyrics in Ol' Man River and Can't Help Lovin' Dat Man have been subject to repeated alterations – in its depiction of racism, some productions of Show Boat, as well as the text of the musical, have themselves been accused of racism. It does seem odd now, for example, that in the early productions the part of Julie was typically played by a white woman – in the 1951 film, the role fell to Ava Gardner.

Most notably, a section of Ol' Man River that uses the N-word has either been omitted or the word changed to other terms, including "coloured folks" and the first-person plural "we". Cape Town Opera's version restores the original N-word, with Maidi saying it is the correct choice. "We are not telling a fairytale here," he says. This was the culture and context in which Joe, Queenie and the other river workers lived. "I think it will make the younger audience inquisitive: 'How did this really happen? Why are they saying this word?' But at this point in time, this is what was happening."

There are segments of Show Boat that make for an uncomfortable watch. Honeyman believes it is vital not to gloss over the racism within the story, "lest we forget" the tolls that prejudice and oppression take. But there are some structural issues with the plot that she has had to negotiate.

After Julie sings her second big number, Bill, she sacrifices her spot in a Chicago nightclub show to would-be performer Magnolia, the white daughter of the show boat's captain. Then she disappears.

“As far as the rights go, you have got to do what the script is. In the original, Julie just leaves and goes on a bender and that’s the last you hear of her. But I have visually integrated her story right the way through to the end, so we can see what being held in a miscegenation case does to a life. In my version, it is completely tragic.”

The second act, Honeyman says, “deals with women’s pain”, while also containing what is known in musical theatre parlance as “11 o’clock numbers”, or the dizzying spectacles that typically occur late in a show to keep the audience primed for the finale. Ziegfeld was “clever enough to make sure he wasn’t presenting a big tragedy”, she says.

Although its lyrics are quite fatalistic – "Fish gotta swim and birds gotta fly / I gotta love one man 'til die" – Can't Help Lovin' Dat Man is the number that has people clicking their fingers, humming along and just generally feeling like they are having a fabulous night out. It is first performed in an ensemble led by Julie, who knows all the words to the astonishment of Queenie, who identifies it as an African-American song. "You have Ol' Man River, which is quite serious and sombre, and then immediately afterwards you have this direct contrast," says Kenned. "It's upbeat and it is fun – there is that vivacious energy on stage. If the audience gets infected by that, then the number has been a success."

The Cape Town Opera production of Show Boat is big by the standards of modern musicals, with 48 people on stage, all in sensational voice. Hours of costume ironing and wig preparation take place before each performance, as a company of almost 100 people recreate both the 1880s and the 1920s. As the ruffled silk dresses give way to slinky Charleston outfits, much of the happiness in Show Boat is revealed to be hollow. But while Magnolia suffers along the way, she is granted both stardom and the hope of reconciliation with her "no-account" husband.

There is no such solace for Julie.

Honeyman remembers her mother singing songs from Show Boat, her favourite musical, when she was growing up in Cape Town. "I knew all the songs anyway," she says. But as a veteran of Johannesburg's anti-apartheid Market Theatre, directing Show Boat is as much a political project as it is personal: "Anybody who is sensitive to racism will see the levels we are trying to work on. This is an essentially American play, with an essentially South African texture to it." Show Boat is at the Bord Gáis Energy Theatre from July 29th to August 2nd. See bordgaisenergytheatre.ie