For everyone asking for metadata, I recommend the Schoenberg Database of Manuscripts (link: http://dla.library.upenn.edu/dla/schoenberg/index.html http://dla.li

For everyone asking for metadata, I recommend the Schoenberg Database of Manuscripts (link: http://dla.library.upenn.edu/dla/schoenberg/index.html http://dla.library.upenn.edu/dla/schoenberg/index.html). They have a weekly data dump, as well as a three-year overhaul underway. Wonderful, wonderful community around it, with a deep commitment to open data. If you have any suggestions for the database's future you'd like to see, I'd be happy to say it forward or put you in touch with somebody (I interned there last semester).