There is a "music score" format under listed under the “Search Entire Collection” pull-down menu in the catalog. You can search by keyword or just enter an asterisk (*) to browse a list of all musical scores we have.
As far as databases, try:
Classical Scores Library: Volumes 1-4
International Music Score Library Project (IMSLP)
Recent Researches in Music Online (RRIMO)
UCLA's Sheet Music Consortium offers a "digitized sheetmusic" option under the search box. It will bring up results for freely-viewable scanned pieces.
Schneider Music Library houses a small collection of sheet music.
Music Librarian, Mark Blair.
https://www.library.txstate.edu/music https://www.library.txstate.edu/music/services-and-information/staff.html https://guides.library.txstate.edu/subject-music
Thank you.