“Do you know the Metro club?” I feign recognition to the 82-year-old father of Ethio-jazz, Mulatu Astatke, who knows the UK capital’s vanished haunts better than I do (the Soho venue closed down decades ago). By then, he had immersed himself in the city’s 60s jazz scene, befriending Ronnie Scott and the saxophonist Joe Harriott, with whom he occasionally jammed across Soho’s clubs, as well as musicians from Africa and the Caribbean.

But when he returned to “Swinging Addis” years later with the new genre he’d innovated in England and the United States, the audience at one of his first performances weren’t so taken by his fusion of jazz riffs with the harp-like begena. “Stop,” Astatke was told. “No more!” He didn’t say a word. Instead, he bowed, said his thanks and walked off. “I said: ‘I’ll show you,’” recalls Astatke in his smoky voice. “‘One day, I’ll come back and show you.’”

True to his word, audiences around the world have since fallen under the spell of his otherworldly music. We meet days after Astatke’s performance at London’s Royal Festival Hall in June, which is expected to be his last performance in the UK. Like much of his music, he’s difficult to place at first. Dressed in all black, he blends into an armchair in the almost empty lounge of a north London hotel with art deco flourishes. It was beautiful to see the packed audience appreciating Ethiopian jazz, he tells me.

But it wasn’t easy trying to do something new. The jazz he has built across more than a dozen albums is mesmeric, layering the distinct pentatonic scales of traditional Ethiopian music with western-style jazz and funk, and infectious Afro-Latin rhythms. He weaves in traditional instruments – the krar, masenqo and kebero – as well as religious chants dating back to the fourth century. “Ethio-jazz is a beautiful science,” he says, leaning back into his chair. “You can hear jazz, you can hear 12th notes, you can hear the 5th notes and everything all combined together.”

Long before the Ethiopian giant honed his sound, he was sent by his parents to a boarding school in Wrexham, north Wales, at 16, set on studying aeronautical engineering. It was there he picked up the trumpet and was encouraged toward a career in music. Subsequent spells at London’s Trinity College of Music and Boston’s Berklee College of Music, as its first ever African student, followed.

Throughout the late 60s, Astatke shuttled between New York – where his group, the Ethiopian Quintet, recorded the albums Afro-Latin Soul 1 & 2 – and Addis Ababa, where he began recording singles for Amha Records, the country’s first independent label, in 1969. “I really wanted to be different, I wanted to be myself, I wanted to be Mulatu,” he says of the years spent honing his sound. “Then once I created Ethio-jazz, I became myself.”

His Ethio-jazz is rooted within the musical culture of a country that, unlike many of its neighbours, has enjoyed independence for most of the last 2,000 years (with the exception of a brief Italian occupation from 1936 to 1941). Astatke had returned to Addis with his own vibraphone and electric keyboards, to a golden age of nightlife and music under Emperor Haile Selassie’s reign (think saxophonist Getatchew Mekurya, singer Mahmoud Ahmed and keyboardist Hailu Mergia, to name a few), which served as fertile ground for experimentation.

With his reputation growing, in 1973 Astatke performed in Addis with Duke Ellington, who was touring Ethiopia and Zambia on a state-sponsored trip. He “never expected this from an African”, the US jazz legend told Astatke, as the saxophone section played Ethio-jazz. “He loved it,” he recalls today, wistfully. “It was so good, so beautiful.”

The era of a famously wild nightlife under Selassie came to an end when the emperor was deposed by a Marxist regime in 1974, and a repressive period followed for nearly two decades in which hundreds of thousands of Ethiopians were killed, jailed or exiled.

My questions about Astatke’s performances for Selassie and life under Ethiopia’s Communist junta are, however, met with reticence. “I have no involvement with the military, I have no involvement with politics, I have no involvement with nobody. I live peacefully. That’s how I survive,” he says firmly. Why the lack of interest in politics? “I don’t love it. You don’t respect politicians. I love my country, I love my culture, I love the people. That’s all. Nothing else.”

Astatke wants to ensure that Ethiopia’s cultural contributions don’t go unnoticed. Speak with the musician long enough and each conversation will inevitably bend to the country’s “bush people”, who he feels have yet to receive credit for their musical contributions. Take, for example, the diminished scales used by American saxophonist Charlie Parker (imagine leaps or half-steps in sound); the Derashe tribe in southern Ethiopia, he says, play the same scale. “Who is first? Is it Charlie Parker or this tribe?” he says. “We never give respect to these people.”

As he lists off other examples that speak to the forgotten African influence in western music, it feels like I’ve stumbled on to a gameshow. Which came first, the masenqo or the cello? The energised cha-cha and mambo music he heard in a visit to Cuba when he met Fidel Castro, or the similar sounds found in Nigerian, Ghanaian and Tanzanian rhythms?

Astatke jumps then to Japan, a country whose traditional music uses the same five-note scale as Ethiopia. (“Who was first? Who created? Where did this come from?”) Then he compares Beethoven and Tchaikovsky, who famously had distinct musical notations, to St Yared, a sixth-century Aksumite composer credited with creating his own musical notations (“How much respect do you give to him?”). Astatke recalls being invited to lecture at a university in Ethiopia, where students couldn’t name the mountain beyond the classroom but knew the German and Russian composers. “We don’t do any research, we go more to Europe instead of doing research on African people,” he says. “I feel sorry for the educational system in the world, culturally.”

In the 1990s, Astatke visited various Ethiopian indigenous communities – the Derashe in the south and Gambella, home to the Nilotic Anuak people – where he was immediately welcomed. There he would have long discussions and, on occasion, stay in small huts. The high respect he holds for them is palpable: “The bush people created Mulatu, because I became a musician by listening to the masenqo.”

His manager, sitting at the table with us, gets out his laptop and pulls up a joyous performance by Astatke with members of the Derashe tribe, one of the several communities he brought to the studio in the 1990s. A second video, from the 1970s, shows him performing with traditional musicians playing the krar. “I became a musician by listening to these people,” he says, “they created me.”

Astatke will soon return to Addis Ababa where he’s expecting an audience at the African Jazz Village he opened in 2013, now run by his son. The venue still draws international visitors and spotlights local musicians today.

What’s next? He toys with the idea of playing new music at the club in Addis. His most recent album, Mulatu Plays Mulatu, was a new arrangement of his classics with his UK band, but his next will feature musicians from “the bush” as well as those in Addis. But there is no name for the project yet, he insists – it is still a work in progress.

“Promoting Ethiopia, promoting our cultural people to the world, that’s what makes me so great and happy,” he says. “It took me years and years, but finally we made it.” Only then, do I see a smile beneath Astatke’s serious demeanour. “Give respect to Africa,” he says again, “and the bush people.”

Mulatu Astatke’s album Mulatu Plays Mulatu is out now on Strut Records.