One of Japan’s biggest girl groups, AKB48, have released a single that was partially generated by artificial intelligence, after a televised songwriting contest.

The competition saw composer Yasushi Akimoto, whose songs have collectively sold more than 100 million copies, go head-to-head with an “AI Akimoto” trained on his writing style.

They each composed a new song for AKB48 as the group celebrated their 20th anniversary. Fans were presented with both tracks and asked to vote for their favourite.

The results were announced live on Japanese TV – with the AI song, Omoide Scroll, winning by more than 3,000 votes. “What? You’re kidding me!” Akimoto responded as the scores were revealed.

The song has now been uploaded to streaming services as AKB48’s 67th official single.

The real Akimoto’s song, called Cécile, has been deleted from YouTube.

The Japanese music industry will be watching closely to see how fans react to Omoide Scroll, now they know it was machine-generated.

Japan’s Oricon singles chart will provide the ultimate litmus test – as AKB48’s last 53 songs have gone to number one.

If their new record breaks that streak, it may be regarded as a rejection of the technology.

Yasushi Akimoto is one of the most prominent writers and idol-makers in Japanese pop, and was once called the “Steve Jobs of otaku” – a Japanese term for people with an obsessive interest in a specific hobby such as anime or video games.

He is responsible for creating chart-topping bands including Onyanko Club, AKB48 and their various spin-offs; and is a professor at the Kyoto University of Art and Design.

For the AI songwriting contest, Google’s Gemini software was trained on Akimoto’s writing style, including essays, vocabulary and songwriting techniques.

It then generated the lyrics for a new song and chose which of AKB48’s members (there are 43 in total) would perform the lyrics and choreography.

The song itself was completed and arranged by humans, although some Japanese media reports say the AI software was also responsible for the melody.

Akimoto followed the same process, and the two songs were put to a public vote, without revealing which was which.

The entries were:

• Cécile. Written by Akimoto, it is a Motown pastiche with a French twist. The lyrics describe a girl’s obsession with her female best friend: “I copy the way you style your hair / Please don’t notice my love for you.” Akimoto chose AKB48’s current band leader Kuranoo Narumi to sing the lead vocal.
• Omoide Scroll. Written by AI Akimoto, takes a more modern approach, with a lite-techno backing and a group chorus. The lyrics depict heartbreak in the smartphone era: “I stop the scroll of memories / Like the battery light fading out.” After analysing interviews with AKB48, the AI chose newcomer Ito Momoka to perform the song, highlighting her ability with emotional storytelling.

In the run-up to the contest, Akimoto was philosophical about the process.

“Everyone keeps asking me, ‘What will you do if you lose?’,” he said.

“It’s fascinating to think that AI could create such a great song, and I’m looking forward to it.

“I’d like to hear [fans] say, ‘I never thought of that!'”

When the votes were counted, the AI won by 14,225 votes to Akimoto’s 10,535.

Speaking on live television, the musician admitted he was “disappointed” by the loss.

“That’s a shame. I wrote it with all my might,” he said.

The AI program was also asked for a response, and commented: “Maybe the real me was trying to show something new by losing this time.”

“Shut up!” Akimoto retorted, prompting laughter in the studio.

The composer was comforted by Grammy-winning jazz musician Hiromi Uehara and former AKB48 singer Sashihara Rino, who encouraged a rematch.

Akimoto laughed off the suggestion, but expressed frustration about technology’s ability to mine data and find the “maximum common denominator”.

However, he conceded: “I think the AI ​​song is a good song.”