Hugh Masekela, The Fridge, London

"Destination Brixton" say the AA notices as you drive through south London, as though the dirt and drugs have been cinematically glamorised away. But glamour has certainly descended, in the form of a 10-day trade expo including a series of concerts to mark the 85th birthday of Nelson Mandela. And where better to kick off, on a steamy summer night, than in a venue called The Fridge?

The interior of this friendly space was a riot of balloons, with pictures of Saint Nelson beaming down from above. As a warm-up act we got a snatch of the London African Gospel Choir, then on came a band led by a grey-suited gent with a pork-pie hat pulled firmly down over his nose: it was the trumpeter Hugh Masekela.

Given his first trumpet by proto-activist Father Trevor Huddleston, Masekela became a key member of the jazz movement that blossomed in the townships during the early apartheid years. With his friends, the pianist Abdullah Ibrahim (then known as Dollar Brand) and singer Miriam Makeba (whom he later married), Masekela beat a path to New York where he absorbed the music of Miles Davis, Dizzy Gillespie, and Thelonious Monk.

Masekela then found himself exiled for decades, but that did not prevent him exerting a seminal influence on South Africa's indigenous jazz. Listen to him and his colleagues in their Jazz Epistles group around 1960, and you'd almost think it was vintage Dizz and Bird; listen to the work they produced later, and you'll see how different South African jazz is from its American equivalent. The juices are flowing, from African tribal roots.

At the Fridge Masekela passionately invoked those roots. "Come on, let me hear you all sing this, because there's a lot of you from home," he shouted, before another reprise of a Zulu song his audience knew well. He blew and sang, his audience sang and clapped, and whole sections of the crowd swayed in close-formation dance.

The song he'd begun with was "Send Me", a slow hymn traditionally sung at funerals and revivalist church celebrations, to which he put his own stirring words: "I wanna be there/ When the people turn it around/ When they triumph over poverty... I wanna be there/ For the victims of violence/ I wanna lend a hand..." After that came "Conchita", his lusciously Cuban tribute to his country's Afro-Latino community, and then launched into a medley of Zulu songs.

In musical terms, this was a pretty painful evening, thanks to the fact that the Fridge amplified everything to an insane level: one more reason for getting Masekela's fine new album, Time, and savouring his art.