The musician Ryuichi Sakamoto, who has died aged 71 of cancer, spent his life as a restless traveller, both personally and musically. "I was born in Japan but I don't think I'm Japanese," he said in 1988, two years before he moved to New York. "To be a stranger – I like that attitude. I don't like nationalities and borders."

A founder member of Tokyo's pioneering computer-pop trio Yellow Magic Orchestra, whose work between 1978 and 1984 has proved a lasting influence on hip-hop and electronica, Sakamoto was able to combine his skills as an academically trained musician with an aptitude for electronic music and an ear for countless musical styles. He sustained a lengthy partnership with the British musician David Sylvian after first working with his band Japan on the track Taking Islands in Africa from the Album Gentlemen Take Polaroids (1980), following which the duo collaborated on the double A-side Bamboo Houses/Bamboo Music (1982).

In 1983, Sakamoto achieved a peak of commercial visibility by not only writing the soundtrack for Nagisa Oshima's film Merry Christmas, Mr Lawrence, but also co-starring in it (as Captain Yonoi) with David Bowie. The soundtrack, which won him a Bafta for best film music, contained the Sakamoto/Sylvian composition Forbidden Colours, a vocal version of the film's main theme, which was a Top 20 hit in Britain.

Soundtrack work became one of the main planks of Sakamoto's career. He won an Academy Award (along with his fellow composers David Byrne and Cong Su) for his soundtrack to Bernardo Bertolucci's The Last Emperor (1987), in which he also had an acting role, and worked with the director again on The Sheltering Sky (1990) and Little Buddha (1993).

Sakamoto scored the 1990 film version of The Handmaid's Tale, Pedro Almodóvar's Tacones Lejanos (High Heels, 1991), and Brian De Palma's Snake Eyes (1998) and Femme Fatale (2002). Oliver Stone hired him for the soundtrack to his TV series Wild Palms (1993). Alejandro González Iñárritu used some existing Sakamoto recordings in his 2006 film Babel, then recruited him to write the score for his multiple Oscar-winner The Revenant (2015). For the opening of the 1992 Barcelona Olympics he provided El Mar Mediterrani.

Sakamoto released solo albums regularly between 1978 and 2017, many of them reaching the Top 30 in Japan but not registering on charts elsewhere, as well as six live albums and a string of compilations. However, Sakamoto's subtle, exploratory music earned him a charismatic reputation that drew international guest stars to his projects.

On B-2 Unit (1980), he collaborated closely with Andy Partridge from XTC, and the electrofunk track Riot in Lagos proved inspirational for the likes of Mantronix and Afrikaa Bambaataa. Thomas Dolby featured on the pulsating Field Work from Illustrated Musical Encyclopedia (1986), the track accompanied by an ingeniously conceived video, while for Neo Geo (1987) Sakamoto enlisted Iggy Pop, Bill Laswell, Bootsy Collins and Sly Dunbar.

Brian Wilson and Robbie Robertson appeared on Beauty (1989), an album that spanned rock, technopop, flamenco and classical Japanese music. Heartbeat (1991), on which Sakamoto tried rap, funk and jazz, and lyrics in French, Japanese and Russian, numbered Youssou N'Dour, Arto Lindsay, Bill Frisell, Sylvian and John Cage among its contributors. In 1993, Sakamoto co-produced Aztec Camera's album Dreamland.

Born in Tokyo, Ryuichi was the only child of Keiko (nee Shimomura), a hat designer, and Kazuki Sakomoto, a literary editor. While attending the same progressive primary school that once taught Yoko Ono, he was already writing music for the piano with their encouragement.

The American presence in postwar Japan introduced new western influences to the country, and Sakamoto was enraptured by the Beatles and the Rolling Stones. He attended Tokyo's University of the Arts to study music composition, and felt a strong affinity for the compositions of Claude Debussy, in which he discerned an Asian influence. However, in addition he soaked up the work of contemporary composers such as Cage, Pierre Boulez, Györgi Ligeti and Stockhausen, as well as jazz musicians including John Coltrane and Ornette Coleman.

His early compositions were in an avant-garde vein, while he also performed with free jazz bands and played keyboards with the folk singer Masato Tomobe. He graduated with BA and MA degrees, having studied classical and assorted world and ethnic music, and taken his first steps in electronic music by working with Moog and ARP synthesisers.

He formed Yellow Magic Orchestra in 1978 with Haruomi "Harry" Hosono and Yukihiro Takahashi, whom he had met when they worked together as session musicians. Combining electropop with stylish graphics and costume design, the trio brought wit and warmth to the use of electronics, which contrasted with the studied alienation of European counterparts such as Kraftwerk or Gary Numan.

YMO released eight studio albums during their original lifespan, all of them climbing high in the Japanese charts, and three of them reaching No 1. The group inspired Beatlemania-like hysteria in their homeland. "We were very big, that's why I hated it," Sakamoto said. "We were always followed by paparazzi."

YMO's albums made little chart impact outside Japan, but their influence was nonetheless widely felt, not least in their innovative use of electronic sequencers, drum machines and sampling. Firecracker, from their 1978 debut album, was itself sampled in Afrika Bambaataa's Death Mix. In 1980 they had a Top 20 hit in the UK with Computer Game (Theme from the Invaders), which chimed with the craze for the Space Invaders game. Behind the Mask, first conceived for a Seiko wristwatch commercial and then included on their album Solid State Survivor (1979), became a Top 20 UK hit for Eric Clapton; a version by Michael Jackson appeared on the posthumous album Michael (2010).

YMO paused their activities in 1984, though the trio continued to collaborate on each other's solo work, and they reformed to make the album Technodon (1993). They subsequently reunited several times for recording and live performances, their last shows being for the No Nukes 2012 festival in Chiba, Japan, and the 2012 World Happiness festival in Tokyo.

In his teens in the late 1960s, Sakamoto had been a hippy with leftwing political beliefs – "not 100% Marxist, but kind of" – but he gradually became disillusioned with the failure of political movements to effect significant change. He decided that his music was not the place for social or political messages, observing that "I've changed from an avant-garde person to a pop person," though he would subsequently support causes he felt strongly about.

He campaigned for changes to music copyright law, which he considered outmoded in the internet era, and founded Commmons, a collaborative platform to assist aspiring musicians. He formed a group of musicians called NML (No More Landmines), which featured Brian Eno, Sylvian, Kraftwerk and the other members of YMO, and in 2001 they released the single Zero Landmine.

In 2006 he launched the Stop Rokkasho movement by releasing the track Rokkasho (by a group of musicians dubbed Team 6), in protest at the building of Japan's Rokkasho nuclear fuel reprocessing plant, and he campaigned to have the Hamaoka nuclear plant shut down to avoid a repeat of the 2011 tsunami disaster at the Fukushima facility. He and Byrne teamed up to record the single Psychedelic Afternoon to aid tsunami survivors.

His solo work continued to explore a huge variety of styles. In 1982 he had ventured into medieval and Renaissance music on the album The End of Asia, a collaboration with the Japanese early music group Danceries. Smoochy (1995) was a detour into easy listening, while Discord (1998) comprised an hour-long orchestral composition.

The album 1996 was a selection of Sakamoto pieces arranged for piano trio featuring the Brazilian cellist Jaques Morelenbaum, and Sakomoto reunited with him and his wife, Paula, a singer, for two albums in celebration of the bossa nova composer Antônio Carlos Jobim, Casa (2001) and A Day in New York (2003). In 1999, his multimedia opera, Life, was performed in Tokyo and Osaka.

Meanwhile, he struck up a fruitful collaboration with Alva Noto (a pseudonym of Carston Nicolai), which resulted in a string of electronica albums including Vrioon (2002) and Insen (2005), culminating in Glass (2018). With the Austrian guitarist and composer Christian Fennesz he recorded Sala Santa Cecilia (2005), Cendre (2007) and Flumina (2011).

In 2014 he was diagnosed with throat cancer, but by the following year was feeling "much much better". His recovery from illness inspired the creation of his album Async, hailed as one of 2017's finest forays into experimental electronica. Its making was documented by Stephen Nomura Schible in the film Coda (2018).

His final album, 12, was recorded during hospital stays in 2021 and 2022, and released in January. In December, he livestreamed a solo piano concert from Tokyo.

Sakamoto was first married to Natsuko, then to the musician Akiko Yano; both marriages ended in divorce. He is survived by his third wife and manager, Norika Sora, and their two children; and a daughter from his first marriage and another daughter from his second.