Together with musicians, scientists have used AI (artificial intelligence 人工智能) to complete Ludwig van Beethoven’s unfinished 10th symphony（交響樂）.
For a long time, creativity （創意） has been seen as something that can only emerge from human brains, but there are increasing signs that this may no longer be the case.
Beethoven wanted to dedicate his life to his 10th symphony, but he passed away before he could even complete his next masterpiece（傑作）. Around 1817, the Royal Philharmonic Society in London commissioned（委託）Beethoven to write his 9th and 10th symphonies. Beethoven completed the 9th Symphony in 1824, which concludes with the timeless “Ode to Joy”. He started work on his 10th Symphony later, but due to deteriorating（不斷惡化的）health, he was not able to make much headway. He died in 1827 and left behind some musical sketches and a handful of ideas he had jotted down. Ever since, Beethoven fanatics have puzzled over what the 10th Symphony could have been like.
Walter Werzowa is a composer in Vienna who studied Beethoven for years. In early 2019, he and a group of Beethoven fans undertook a challenge（挑戰）. They took the rough sketches of Beethoven’s 10th Symphony and tried to complete it. They were complacent（自滿的）at the beginning to think that they could do that in half a year what Beethoven would do in many years. But Werzowa and his team had a bit of help. Ahmed Elgammal, professor at Rutgers University of computer science and director of the Art and Artificial Intelligence Laboratory, helped the musicians by using AI to finish the masterpiece.
“The way AI generates （產生）music or learn about music is very similar to the way right now – you’re writing an email, for example. The email tries to guess what the next word is for you. So in music, we’re trying to teach AI how to predict what the next note is. And by looking at lots and lots of music, AI fundamentally can learn how to do that,” explained Dr Elgammal.
The scientists started by teaching AI on a broad range of classical music – Bach, Mozart, Haydn, and anything that would have been available to a 17th century Ludwig van Beethoven. Once they had done that, they took the AI within the next level. They gave AI access to all Beethoven works and teach it how Beethoven would compose.
“And because music is very structured and very mathematical, AI can really excel（擅長）at that. AI can really capture（捕捉）how Beethoven would continue or develop on a theme,” continued Dr Elgammal. The challenge was initiated by Matthis Röder, Director of the Karajan Institute, an organization in Salzburg, Austria that promotes music technology. Apart from Austrian composer Walter Werzowa and AI specialist（專家）Ahmed Elgammal, the team also included computational music expert Mark Gotham and Robert Levin, a musicologist from Harvard University. In June 2019, these experts in various fields gathered and discussed how fragments could be turned into a complete piece of music and how AI could help solve the puzzle, while still remaining faithful to Beethoven’s process and vision. With a lot of hard work, Beethoven’s 10th Symphony was finally brought to life, nearly 200 years after the death of the composer. AI has helped to create something that Beethoven himself might have written. To mark the 250th anniversary of his birth, the 10th Symphony, created with the help of AI, was premiered（首演）in Bonn, Germany in October 2021 as part of the Beethovenfest, a festival of classical music dedicated（奉獻給）mostly to the music of Beethoven.
