Orchestre de Poly-Rythmo, Barbican, London

We didn't know we'd missed them. TP Orchestre de Poly-Rythmo de Cotonou, to give them their full name, have been stars in Benin since 1968, but made their European debut in Paris this month, and were known here if at all for low-key, recent compilation CDs. And yet, from the moment this 11-piece band file on stage, the crowd act as if they have been waiting for them for years. The tremendous show that follows ensures it will be much less than 41 years before they return.

Benin's traditional vodun, or voodoo ceremonial rhythms, modernised with the rock, soul, Afro-Cuban and West African high-life sounds current when they formed, are the roots of Poly-Rythmo's twitching, bustling funk. The two key musicians of their heyday, guitarist Bernard "Papillon" Zoundegnon and drummer Yehouessi Leopold, are dead. But former rhythm guitarist Philibert Agbahoungba approximates the former's high, jabbing phrases, metallic flash and precise economy. Keyboardist Degbo Loko adds more of the surprising flourishes that stud the Orchestre's sensually engaging, serpentine percussion, rolling easily from boogie-woogie into psychedelic high-life.

There are inner dramas at work in this revival. Rebellious star singer Vincent Ahehehinnou left them in 1978, and Maillot had to convince the band he must return. This soul singer and exuberant loose cannon spins and shadow-boxes across the stage, buzzing with unburned energy between songs. He's the magnetic centre of attention, leaving others in the band looking a little put out, though finally pleased at his return. His fellow lead singer, Cosme Anago, comes into his own on a more traditional vodun chant, over barer beats. Soon, there are little flashes of electric guitar, and Augustin Loko's sax blows jazzy accompaniment, as the chant morphs into outrageously tight yet mentally loosening funk. They have led us gently to this heart of their mysterious art. Now, rotund trumpeter Vital Assaba feels free to high-step across the stage, exhorting aisles filling with gyrating dancers from the previously sedate crowd. As Ahehehinnou notes, it's all a wonderful 64th-birthday present for "our chief", band-leader Clement Melome. Melome takes the lead vocal at the start of an inevitable encore that ends in pure voodoo chants. They were rusty in Paris. They are fully potent, late-blooming stars now.