Two singers, an imam and a rabbi, trade verses and then leave the stage hand-in-hand. Behind them, dozens of Jewish and Muslim musicians play rousing songs that celebrate, in two languages, their love of a single country. This was the improbable scene at recent concerts in Marseilles, in Paris and at the Barbican Centre in London by the Algerian chaabi band El Gusto.
It was, however, perfectly fitted to the music they played. Chaabi is the rollicking, nostalgic, disreputable product of centuries of invasion, occupation and migration to (and, more recently, from) Algeria. The 15th century brought Jews recently expelled from Spain; the early 17th brought Spanish moriscos, Christian converts of Arab descent. Many settled in Algiers - a migration commemorated in chaabi's Andalusian elements as well as the orchestra's name, which is Spanish for "the good feeling". The 19th and early 20th centuries brought French colonists - the pieds noirs, who contributed chanson, French folk songs and accordions; in 1942, American GIs introduced jazz, blues, boogie-woogie and, incongruously, the banjo.
The resulting musical patchwork, captured on the band's first album, mixes the secular with the sacred, the celebratory and the reflective. A track called "Min Yaati Kalbou Lil Melah" ("Who Gives His Heart for the Beauties?") sits next to "Lalla Fatima", a song in praise of the daughter of the Prophet. The sound, created by a beefed-up, 30-strong version of the traditional small chaabi band, is uncompromising: strong Arab-style vocals rise over massed violins, ouds, guitars, a reed flute and percussion. Compared to the now-familiar desert blues of North and West Africa, it makes few concessions to western ears.
The impression is reinforced by the audibly straightforward album production. The songs were recorded live, overlooking the casbah, in the ramshackle Algiers Conservatoire where Hadj el-Anka, father of El Gusto's leader, Abdel Hadi Halo, taught chaabi 60 years ago. Given that El Gusto are signed to Honest Jon's, the west London label co-owned by Damon Albarn, the lack of sonic airbrushing is impressive. "We wanted to share real chaabi with people," says Mark Ainley, Albarn's partner in Honest Jon's. "It doesn't work if you try to change it around."
But El Gusto's chaabi is inevitably different from the music some of these artists played together 60 years ago in the "streets, houses and coffee shops" of the tumbledown casbah. The Jewish and Muslim musicians, separated when Algeria's Jewish population fled to France in 1962, were reunited largely through the efforts of a young Irish-Algerian film-maker - Safinez Bousbia, whose documentary film El Gusto: the Good Feeling is due for release next year, invited Albarn and Honest Jon's to collaborate on the project. Despite the rapturous press response, El Gusto is not a simple re-creation of a musical and political golden age. History and politics, not to mention the 750 kilometres of sea between Algiers and Marseilles, have intervened.
However unwillingly, the album and concerts are haunted by the traumas Algeria has suffered since 1962. The Jewish musicians were reluctant to return there for the recording because of the threat of Islamist violence, so it was done without them. As a result, it omits the melancholic chanson sound and French-language tales of exile of the recent concerts. The size of the band - at full strength, 40 musicians - is another anomaly. "Originally, chaabi bands had fewer than ten musicians," says Ainley. "They had to fit into someone's house." The duet between the imam and the rabbi is an ahistorical gesture: when Jews and Muslims lived side by side in the impoverished casbah, it was unnecessary to make a point of the communities' (relative) harmony.
"This is more about 2007 than about the 1950s," says Natalya Vince, a scholar of modern Algerian history. Algiers in the 1950s was a co lonial city, its communities racked by tensions heightened by the French rulers. Jewish Algerians were offered French citizenship, a privilege denied to Muslims unless they renounced their right to be subject to sharia law in the personal sphere - to become, for legal purposes, non-Muslim. The inhabitants of the casbah, in particular, struggled with poverty and discrimination. Chaabi, born in the crowded casbah streets, was the down-at-heel entertainment of the working classes. But Vince says: "In comparison with the civil violence and Islamic fundamentalism of the 1990s, when being Jewish - or being a woman, or a teacher of French, and so on - could get you killed, the 1950s do look like a golden age."
Perhaps because of this, chaabi's Arabic meaning - "of the people", meaning the people of Algiers - is still surprisingly accurate. At the Barbican concert, young Algerian expatriates danced, ululated, waved mobile phones and roared along to chaabi standards played by the 70- to 90-year-old musicians. Even potentially unsettling songs had the same reception: the audience sang happily along with Luc Cherki's accordion-punctuated ballad of a colonist's exile, "Je suis un pied noir". The success of El Gusto's brand of nos talgia may be helped along by hindsight, but if their music offers a glimpse of another Algeria - a country, however imperfect, of tolerance and cross-fertilisation - that is no bad thing.
"Abdel Hadi Halo and the El Gusto Orchestra of Algiers" (Honest Jon's) is out now