What metadata are you planning to record? You can use Music Encoding Initiative (http://music-encoding.org/) to record the music notation in addition to metadata about the work itself. The University of Virginia Library is undertaking a project to describe a sizeable collection of 18th century European printed music in EAD (not unlike a manuscript collection). MEI may be applied to encode music notation for these works in the future.
American Numismatic Society
I am involved in a project in which we are struggling with the complexities
and idiosyncrasies of metadata involving classical music. I was wondering if
the members of this group could suggest any metadata standardization efforts
which address many of these challenges. We do not want to try and re-invent
things that may already exist and I am very interested in leveraging work
that has been done by people with more expertise in this field than I or any
of my colleagues.