A composição não é do Bach, é uma adaptação para órgão feita por Bach, de uma peça para coral composta por Dietrich Buxtehude .
http://www.theepocht...-9-1/45541.html
Early Bach Manuscripts Reveal Teenage Talent
Reuters Sep 01, 2006
Johann Sebastian Bach (1685-1750), considered by many as the greatest of the Baroque composers, was also renowned for his technical virtuosity with the pipe organ and harpsichord. A recent discovery of manuscripts dating back to 1700 reveal Bach's musical ability was remarkable even at an early age. (www.photos.com)BERLIN—Previously unknown manuscripts by Johann Sebastian Bach , recently discovered in Germany, prove that the prolific German composer was a virtuoso even as a teenager, researchers said on Thursday.
The works, one of which is dated 1700 when Bach was only 15 and the other thought to be even older, are copies of other composers' choral pieces, arranged for organ by Bach.
They were found among archives in a library in the eastern city of Weimar.
"We have until now not had anything dated before 1700 and what is particularly important is that these are not just manuscripts but musical arrangements which are particularly demanding," said Christoph Wolff, director of the Bach archive in Leipzig.
"Technically, they are demanding, compositionally they are demanding and they show what the 13- to 15-year-old Bach was capable of," he added. "This is something we have never had any indication of previously."
The two handwritten pieces are copies of "Nun freut Euch lieben Christen gmein" by Dietrich Buxtehude and "An Wasserfluessen Babylon" by Johann Adam Reinken.
The Weimar archives in the Anna Amalia Library have already yielded an unknown early Bach aria, adding to the few surviving pieces which remain from his early career.
Acknowledged by many as the greatest Baroque composer, Bach was born in 1685 and died in 1750. His most famous works include the Brandenburg concertos and the Mass in B minor.