Two long-lost organ pieces by JS Bach performed for first time in 300 years

Two long-lost organ pieces by Johann Sebastian Bach have been performed in Germany, roughly 320 years after the composer wrote them as a teenage music teacher.

Entitled Chaconne in D minor BWV 1178 and Chaconne in G minor BWV 1179, the pieces were added to the official catalogue of Bach’s works on Monday and played in public for the first time in three centuries inside Leipzig’s St Thomas Church, where Bach is buried.

Researchers discovered the two anonymous and undated works in the Royal Library of Belgium in 1992, but it wasn’t until recently that they were able to authenticate Bach as their author.

Peter Wollny, the director of the Bach Archive in Leipzig, said on Monday that over three decades he had amassed about 20 “puzzle pieces” pointing to authorship by the composer. Identifying the copyist who had written down the score, however, proved a challenge.

Several years ago, Wollny’s co-researcher, Bernd Koska, discovered a letter from 1729, with similar handwriting by a hitherto unknown organist called Salomon Günther John, who claimed to have been one of Bach’s pupils in Arnstadt, Thuringia.

It was only when the researchers managed recently to track down an earlier court document written by John with matching handwriting that they were certain that he had written down the score under Bach’s watch in 1705.

“I searched for a long time for the missing piece of the puzzle to identify the compositions – now the whole picture is clear,” Wollny said at Monday’s presentation. “I am 99.99% certain that Bach composed both of these works.”

The pieces are chaconnes, a musical form that typically uses series of variations over a short bass line.

Wollny said the works were “highly individual” and “complex”, containing compositional tools that could only be found in Bach’s music at the time, such as the use of a fugue to weave a single theme into the broader musical tapestry.

“This is an amazing discovery,” Canadian pianist and Bach specialist Angela Hewitt told the Guardian. “They are substantial pieces, and will be an excellent addition to the organist’s repertoire.

“For me they are quite identifiable with Bach’s early style, in which the contrapuntal writing is not yet what it would become, but the imagination, grandeur, and sheer joy in playing are all there in abundance.”

Germany’s federal minister for culture and media, Wolfram Weimer, described the discovery as a “great moment for the world of music”, adding: “This is more than just musical research. Colleagues in the press will write that it is a world sensation, but in truth, it is magic.”

Ton Koopman, the Dutch organist who played the works, said he expected that musicians would perform them regularly in the future. “When one thinks of the young Bach or Mozart, it is often assumed that genius comes later in life – but that is not the case,” he told Agence France Presse.