At a party in 1983, Francis Falceto had an epiphany that changed his life. Falceto had been involved in music for many years, as a curator, programme planner and artistic adviser in his native France and elsewhere in Europe. One day, a friend brought him a vinyl LP from Africa. “I played it at that party and was totally amazed. I made cassettes and sent them to friends who knew African music and they all said: ‘What’s that?’ Not only was this great, it was also totally unknown.”

Once he had deciphered the unfamiliar alphabet on its sleeve, the LP in question proved to be Erè Mèla Mèla by Ethiopian singer Mahmoud Ahmed. It sent Falceto in search of other music from the lost golden age of Swinging Addis Ababa. The resulting series of compilations, Ethiopiques, now runs to more than 20 volumes. Its admirers include Elvis Costello, who says “the spoilt complaints of western pop musicians pale into insignificance compared to the defiant human spirit contained in these recordings”. Last year Ahmed won a Radio 3 Award for World Music and this year Falceto himself was honoured with Radio 3’s World Shaker award for his contribution to world music. On Friday, several of the stars of the series, including Ahmed, will play a sold-out one-off concert at the Barbican in London, the first time they have shared a stage.

The golden age of Ethiopian music ran from 1969 to 1978. In the last years of Haile Selassie’s reign, censorship relaxed sufficiently for an outpouring of musical creativity. Musicians thronged the nightclubs of Addis Ababa and about 500 singles and 30 albums were recorded in that period.

“It was the time of the baby boomers, in Ethiopia as well as in the west,” says Falceto. “And then, Kennedy’s Peace Corps were in Ethiopia. About 6,000 hippie-like youngsters bringing guitars and 45s of James Brown.” The US military also played its part: “There was a base in Asmara [now the capital of Eritrea] with its own cinema, its own clubs, and a radio station that broadcast the weekly charts from the US.”

Ethiopian musicians, who had remained aloof from musical developments in the rest of Africa, mixed these influences from American R&B with their own music into something distinctive and strange. At the time, it was denounced. “When you read the press of the time”, says Falceto, “there are polemics against abandoning the culture and so on.”

Swinging Addis was, as Falceto muses, “the last flames of the imperial regime. Many ends of regimes have hot nightlife, artistic flowerings: the Roman empire, Cambodia.” He bridles a bit, though, at comparisons with the Weimar Republic. “It’s not decadence. It’s a time when the arts have a big space in the life of a culture.”

When Selassie was toppled by the Derg, the communist junta that ruled Ethiopia from 1974 to 1987, all this came to an end. “When the Stalinist military regime came in, everything stopped. Almost overnight, the vinyl stopped, the big bands closed.” Live music died. “There were 18 years of curfew. No meetings were allowed. No groups could work, except for the occasional all-night lock-in at one of the international hotels.”

The loss is incalculable. “Eighteen years is almost a generation. Ethiopians under 50 have no recollection of this golden era. I want to rekindle their memories. That’s why the booklets have photos from those days, artefacts and so on.”

For Falceto, the fascination grew slowly. In 1984, he travelled to Ethiopia to track down Ahmed and invite him to perform in Europe – but the regime prohibited Ahmed from leaving Ethiopia. In 1987, Falceto went to Washington, DC, to meet Amha Eshèté, the founder of Amha records, once Ethiopia’s premier label. “He was in exile from the Derg. He had left Ethiopia with nothing – no papers, no masters.”

Falceto embarked on a detective hunt for master tapes. “I left my other jobs. Little by little, I sank into this weird project.” The early Ethiopian records had been pressed in India, Lebanon and then in Greece, where Falceto found a treasure trove.

“It was one of the most beautiful days of my life. I went to Columbia Records in Athens. They had moved buildings but the tapes were well stored.” Falceto is still awed by the serendipity of it all. “Anyone else could have found it. There are many travellers to Ethiopia, after all. There are so many reasons why someone else could have found it.”

That afternoon in Athens, he had no idea how extensive the project would prove to be. The first collection, Golden Years Of Modern Ethiopian Music, came out in 1997. “Initially, I thought I had enough material for about a dozen volumes, but the response was very positive and other musicians wanted in.” The series now runs to 23 volumes and Falceto thinks there is enough material for about 35. “It won’t be the bottom of the barrel by any means. There’s a lot of unbelievable stuff still to be released.”

Many of the musicians whose 1970s heydays are captured on the Ethiopiques series are still working, mostly playing for the vast Ethiopian diaspora, more than 1m-strong in the US alone. Ahmed and the influential arranger and keyboard player Mulatu Astatké both live there, working largely with American bands. At the Barbican, they will be joined by Alèmayèhu Eshèté, who channels the spirit of James Brown, and by the saxophonist Gétachèw Mèkurya. Instrumental support will come from the Either/Orchestra, a Boston-based group.

Falceto has “no idea” who the audience will be. He says: “Ethiopians are crazy about this type of music but they’re not the type to book in advance. They’ll arrive at 10 and be surprised they won’t play all night.”

Falceto is not yet finished with Ethiopian music. As well as the remaining volumes, he is now painstakingly restoring some recordings of traditional music dating back to 1908. “I won’t sell that much but it’s my duty. Most Ethiopians don’t know that it’s even been preserved. Also, there are at least two records of material made by the Italians during the occupation.” And he is setting up a new label, Ethiosonic, for modern material that mixes Ethiopian with other music.

Pressed to recommend five volumes out of the 23-strong series, he hesitates, then offers suggestions. “One, four, seven, eight, 13.” Seven is a reissue of Erè Mèla Mèla, the record with which this all began; four is a set of instrumentals by Mulatu Astatké; the others are compilations. Then Falceto insists on adding just one more: a mystical solo record made by a nun. “And 21. It’s Tsegué-Maryam Guèbrou playing piano, and ... the mood is something else.” The vaults still have more stories to tell.

The Ethiopiques concert is at the Barbican Hall, London, on Friday June 27. ‘The Very Best Of Ethiopiques’ is released on Manteca. The individual CDs in the ‘Ethiopiques’ series are released on Buda music