Most of these sites offer sheet music in .pdf format.
Use OneSearch to find printed music (scores) in the Music Collection:
Printed music and books are located in the "Music Collection," which is part of Education, Music and Media on the Lower Level - West. Use OneSearch, on the Libraries' main page (http://www.bsu.edu/library). Start with keywords, including a composer, title, or number:
From the preliminary results, click "Library Catalog." You will then see the formats ("content types") available: