Given the ethnic make-up of the city it serves – substantially Indian, polyglot African, a smattering of Afrikaans – Durban's Playhouse is a surprise, because both inside and out it's a faithful half-timbered replica of Shakespearean London. But this culture-shock is no stranger than that on stage, where boys in township-chic jostle with elders in tribal robes, and women parade in a glorious blend of fabrics and styles evoking West-African-village-cum-colonial-pomp. The singing on stage alternates between Zulu song and township choral, while the accompaniment from the pit has a Puccinian gloss, except for those moments when all instruments are hushed for the ugubu – a one-string bow, whose notes steal through the air like a spooky whisper. Welcome to Princess Magogo, the world's first African opera.
In the stalls are dozens of African princes, one of whom makes a speech of thanks after the show. This is Mangosuthu Buthelezi, resplendent in his gold braid as South Africa's Minister of Home Affairs. His gratitude is personal, however, because the opera's heroine is his own mother. "This is not just her story," he declares. "It reflects where we come from, and the sufferings and oppression we have endured. It's the story of black Africa."
Set largely in the Twenties, the opera follows the fortunes of Princess Constance Magogo, daughter of the Zulu king Dinuzulu kaCetshwayo. It reflects political turmoil, and gross violence by white colonials, but its armature is the family life of its central figure. For a princess in patriarchal times, she was extraordinarily liberated, singing about the lovers she had before her royal marriage; and her songs were oral history, designed to bolster the patriotism of her Zulu people.
The Princess's face in photographs has the same sweet modesty one now observes in her son (a political peacemaker maligned by radicals of every hue). Moreover, Sibongile Khumalo, who incarnates her on stage, both looks the part and – to a remarkable degree – also sounds it. This is partly thanks to her long study of extant recordings (in one aria she matches Magogo's husky delivery breath for breath). But, as she explains to me, it's also partly because she knew the princess.
"I remember one holiday when our family went to stay near her home, and my father told me to sit at her feet and listen to her sing. I couldn't see why it was so important – I wanted to play – but it was clearly the hand of destiny. I can see her now as an old lady, sitting there holding her ugubu with intense pride and enjoyment, just playing and singing all day." Princess Magogo's songs, in a slow and stately style known as amahubo, can't be bought in the shops, but Sibongile's versions make a very decent substitute. Amahubo songs, she admits, are very hard to sing, "but the older you get, the better you become".
Next week this South African diva will do a short UK tour, though the music she and her band will be performing here belongs at the jazzy end of showbiz. Khumalo actually started her career as a Lieder-singer, specialising in Schubert and Brahms, and her range and timbre is unique. For a girl born and bred in Soweto when apartheid was at its height, hers is a success story well worth retelling.
Her earliest musical memories are of Radio Bantu – a rich brew of traditional Zulu music, church music, and singers such as Miriam Makeba and the Mahotella Queens. "And in the streets we heard the Salvation Army; when I was small I used to march behind them. Once I followed them so far that I became completely lost. Since everything was communal, we all heard each other's music: some neighbours held church services in their yard, some played drums, some – like my elder brother – played jazz, so I grew up surrounded by myriad sounds."
More importantly, her father ran a choir, with which she played the violin and sang. "Music was his big love, but he only became a professional later, when he started a music department at the University of Zululand." She realised in her teens that professional singing was her vocation. "I wanted to study music at university, but in those days, if you were black, two things had to happen first. You had to get the offer of a place from the university, then you had to get permission to study there from the Ministry of Internal Affairs. I got the one, but was refused the other. There was no reason given, they didn't have to explain. You were just not allowed."
So she went to study at her father's black university, where equal weight was given to European and African music, and where the students were encouraged to emulate Bartok. "We used to go out into the hinterland and record, and bring it back and transcribe and analyse it. And in this way we were able to find a new way of looking at our indigenous music, rather than simply enjoying it as the background to our lives."
After graduation she should have had the musical world at her feet, but apartheid impediments were insidiously ever-present. "I would never have described myself as an activist, but politics dictated many of my decisions. If I got an invitation to perform, my response had to be based on who it came from. And I knew that when I came to record my first album, it wouldn't be of European art songs, even though I'd studied them and could do them well, because that music didn't express who I am."
For black Africans, cultural identity is no simple matter. There's a big debate currently raging over how "indigenous" music should be defined, complicated by the fact that the missionary musical influence runs deep, and by the existence of nine distinct African ethnic groups. Moreover, although Princess Magogo is billed as the first African opera, its composer Mzilikazi Khumalo confessed to me that he was sad that no young African composer could be found to orchestrate his melodies, and that he had to rely on a conservatoire-trained British orchestrator instead.
With designs by South Africa's answer to David Hockney – the painter Andrew Verster – and with the Durban Serenade Choral Society providing the chorus, this impressive production is due to tour the States next year, and it's a fair bet we shall finally see it in London. Meanwhile, we can at least catch its diva.
Michael Church's documentary on 'Princess Magogo' is on BBC World Service this Sunday at 2.30am and 8.30am.
Sibongile Khumalo is at the Spilsby Theatre, Lincs, 24 May; Queen Elizabeth Hall, London, 25 May; Warwick Arts Centre, Coventry, 26 May; and The Lowry, Salford, 28 May