Opera and Ballet Primary Sources
OBPS (Index to Opera and Ballet Sources Online) is an ongoing project aimed at indexing free online primary sources related to various forms of dramatic music in a wide variety of formats. It currently points to more than 25,000 resources including scores, sets of part, mise en scène, violon répétieurs and other violin conductor parts, souffleur parts, concert programs, some archival documents, and many librettos. It offers the advantage of searching across more than 30 digital collections in a single interface while providing a convenient link back to the source in its original context. In addition to the basic points of access (person, title, genre, date, etc.), OBPS facilitates searching in other more specialized categories including RISM A/I numbers and RISM library sigla. The index is updated with additional resources on a regular basis.