German researchers said Thursday (August 31) they have discovered the oldest known handwritten manuscripts of Johann Sebastian Bach. Researchers found the documents in the archives of the Duchess Anna Amalia library in Weimar, where a previously unknown aria by Bach was discovered last year. The library, housed in a 16th-century palace, was badly damaged by a fire in September 2004. While some 50,000 books were lost, the Bach scripts survived because they had been stored in the building's vault. "We so far have not found anything before 1700," said the director of the Bach archive in Leipzig, Christoph Wolff. "And what is especially important is that theses are not just written documents but compositions which are quiet challenging, technically challenging, compository challenging, and that they show us the skills of a young Johann Sebastian at the age of 13 to 15 years. That is new, we never had any prove of that." Both the manuscripts and the aria found last year were unearthed by researchers from the Bach Archive foundation in Leipzig, who have been combing German archives for information about the composer since 2002. The manuscripts will be exhibited at the library from September 1 and at the Bach Archive in Leipzig from September 21.