The Digital Archives of Beethoven-Haus in Bonn, Germany contain original manuscripts, first editions, letters, and pictures from its museum and library collections. There are more than 6000 documents, 1,600 audio files, and 7,600 text files available online from BHB.

http://www.beethoven-haus-bonn.de/sixcms/detail.php?template=startseite_digitales_archiv_en