A decades-old legal dispute between German electro-pop pioneers Kraftwerk and music producer Moses Pelham over alleged plagiarism is being sent back to Europe’s top court by German judges, who say they are still unable to reach a final decision.

Germany’s highest court on Thursday suspended its proceedings in the case, which has been going on for more than 20 years.

To make a final ruling, the court said it wants the European Court of Justice (ECJ) to clarify its definition of the term “pastiche”.

Pelham had used a slightly slowed-down version of a drum sequence from the 1977 Kraftwerk song Metal on Metal in the song Nur Mir (Only Me) by German rapper Sabrina Setlur, which was released about two decades later.

The use of such a “sample” from an old song is a highly common practice in the music industry.

Pelham, however, had not asked for permission.

Kraftwerk co-founder Ralf Hutter felt the sample had therefore been stolen and sued the producer.

In 2019, the ECJ ruled in favour of Kraftwerk, saying musicians cannot sample songs without permission.

However, if the sample was modified in “a form unrecognisable to the ear” copyright would not be violated, the ECJ said.

Germany’s Federal Court of Justice then was meant to make the final decision on the dispute but has now sought further clarification.

The term “pastiche” has been used since EU law was transposed into German law, but it has not been defined.

In general, it means imitations of the style or ideas of artists.

It is unclear, however, whether the definition should include more specific criteria such as humour, imitation of style or homage, the presiding judge explained.

The case is being followed with great interest by the music industry, as it raises questions about copyright protection and artistic freedom.