Mahmoud Ahmed, Queen Elizabeth Hall, London <br/> K'naan, Cargo, London

Voices from the heart of Africa

The QEH has been cramming them in to its African music festival, with separate concerts at 7pm and 10pm, and one can only imagine bands drawing straws for the preferable later slot. If so, Mahmoud Ahmed got lucky, and by the time he appeared the usually fairly reserved QEH audience had had the chance to get sufficiently "merry", to be out of their seats and crowding into the pavement-width space in front of the stage to dance the night away, only a couple of songs into his set.

Now 66, Mahmoud Ahmed has recently become his country's best-known musical export, but it's actually thanks to a body of work that is three decades old. During the Seventies - a period known as Ethiopia's golden age of pop music - Ahmed released a clutch of albums that unselfconsciously mixed jazz, funk, and even rock, with traditional Ethiopian styles. The result was both contagiously danceable and rich with intricate Arabesque melodies.

Many other bands followed his example, but then a period of military censorship completely buried this burgeoning scene until relatively recently when the French label Buda Musique began its mammoth task (it's already on Vol 20) of rescuing all this material from obscurity. Listening to these old lo-fi recordings is the aural equivalent of looking through the wrong end of a telescope - the songs are hauntingly distanced, but all the more alluring for it. It was a joy to finally hear themfully brought to life at tonight's concert: those rolling cyclical bass riffs, the dry edgy rhythm guitar, the rich tone created by the twin-engine power of the two saxophonists, and of course Ahmed's imploring vocals, which are one minute softly seductive, the next desperate with passion.

Yet it was only last summer that the man came out of semi-retirement to consolidate the stir created by these re-releases, and ended up being the surprise hit at Womad. Tonight, from the moment he stepped on stage, he further drove the message home that he's not just some revivalist act past his sell-by date.

Dressed from head to toe in white, apart from the red, yellow and green Haile Selassie silk scarf (Selassie was deposed at the same time that Ahmed and his music were driven underground), he had the charisma and evangelical zeal of, say, Al Green, as he switched from charming crooner of serpentine ballads, to shimmying, hand-clapping, rabble-rouser for the up-tempo numbers. By the time the rolling and tumbling funk of "Belomi Benna" was motoring along like prime-cut James Brown, virtually everyone was up on their feet.

It may have taken Ahmed half a lifetime to reach an international audience, but he still positively glows with vitality and looks like a man who is more than capable of enjoying every minute of this extraordinary upturn in his career. All we need now is a new album.

A hip-hop artist with wit and charm is a rare creature indeed, but K'naan has these qualities in abundance. With a hat pulled down tightly over his short afro, K'naan delivered a series of nightmarish scenarios from his childhood in war-torn Somalia with deadpan succinctness before getting to the understated chorus that goes: "Are you hardcore? Really? Are you hardcore? Hmmm..." It's a dig at his American contemporaries who glamorise a violent lifestyle that most of them have been lucky enough never to have experienced.

K'naan's been there and done that, and having escaped death at the age of 14 (three of his best friends were shot dead), the Canada-based songwriter now preaches cultural unity and peace. If that sounds a little too worthy, let me reassure you - he does it with a focused, lucid passion.

Most of the time it was just K'naan's ability to hold an audience in thrall, a semi-acoustic guitar, and the power of palms slapping taut animal skins, which made his UK debut such an incendiary event.