If you're looking for musical scores, try Google Books. Their collection isn't very big just yet, but more are added all the time. Searching can be tricky, so try searching for a unique phrase in the libretto or combine the title of a work with the composer and/or librettist.
Here is a partial list of Opera Scores found in Google Books: http://artsongcentral.com/2008/operatic-vocal-scores-on-google-books/
A list of places where you can find and download free sheet music.
Fraser Hall 203
Service Desk: 585-245-5594Milne Building Renovation Updates
Geneseo Authors Hall preserves over 90 years of works.
KnightScholar Services facilitates creation of works by the SUNY Geneseo community.
IDS Project is a resource-sharing cooperative.
Fraser Hall 203
CIT HelpDesk: 585-245-5588Fraser Hall 208
Website : WLC