Berlin (AFP)

Ludwig van Beethoven had only a few notes on a notebook when he died in 1827. A team of musicologists and computer scientists are trying to extend his 10th Symphony with artificial intelligence.

The final result will be presented on April 28, 2020 in Bonn and should be one of the highlights of the many festivities, which begin Friday, the 250th anniversary of the birth of the composer.

Beethoven had begun working on this symphony in parallel with the famous 9th and his Hymn to Joy known worldwide. But he quickly abandoned the 10th, which was limited, at his death at 57, to a few notes, diagrams and handwritten sketches.

A team of computer scientists and musicologists is trying to extend it by using machine learning software. The software first gutted and analyzed all the composer's works. It then generates, thanks to speech processing algorithms, attempts to extend the partition.

- "Visionary" -

The project was initiated by Deutsche Telekom, based in Bonn, the hometown of the composer. In addition to a communication operation in the middle of the Beethoven year, the group intends to use this work to develop its own technologies, in particular voice recognition.

"Just like language, music is made up of small units - letters or notes - that when combined, make sense," says a spokeswoman for the group to AFP.

When it meets, the team plays the notes written by Beethoven for this 10th Symphony and artificial intelligence takes over. First results were judged a few months ago too mechanical and repetitive, but last attempts would be more convincing.

"The officials have played us first tests. (...) The development (compared to previous tests) is impressive, even if the computer still has much to learn," said the AFP Christine Siegert, director from the archives and research department of Beethoven House in Bonn.

According to this specialist of the composer, his work "can not be distorted by such an initiative, insofar as what is created is obviously not part of the work and that the fragments of the 10th Symphony are themselves only limited work tracks ".

Mrs. Siegert says she is "convinced" that the composer would not have denied this type of initiative being himself a "visionary" in his time. He had composed, she recalls, for the panharmonicon, a kind of organ created in the early nineteenth century reproducing the sounds of forty or so wind and percussion instruments.

- "Risk" -

The British composer and musicologist Barry Cooper, also author of an attempt to complete the first movement of the 10th Symphony, is more dubious.

"I listened to a short excerpt, it did not look at all like a convincing reconstruction of what Beethoven wanted to do, even taking into account the computerized sound and the absence of any contrast between loud and soft sounds," explains he to AFP, judging however that there is "room for improvement" of the result.

For this professor at the University of Manchester, author of several books on the composer, "in any interpretation of Beethoven's music, there is a risk of distorting his intentions". In this case, the "risk" of misrepresenting the work is even greater, the 10th Symphony only exists in the form of timid drafts.

Other similar initiatives have already been conducted on Mahler, Bach or Schubert. With mixed results.

In early 2019, a project, initiated by the Chinese giant Huawei, seized Franz Schubert's unfinished Symphony. The London Session Orchestra had interpreted scores composed by machine learning software. The unpublished passages, according to the European press, had evoked an American film soundtrack rather than the style of the Austrian composer.

© 2019 AFP