For instructions on how to find scores, review Searching for Music Scores.
This database offers complete digitized scores (issued by publishing houses or self-published) and streamed audio recordings of works by several hundred active composers to form the largest continually growing online music library of contemporary music. It also features a virtual music-score reader with a zoom and full-screen options plus biographies of the composers.
All print books (including scores and sheet music) are on the 4th floor of the Knowledge Center. They are classified with the Library of Congress Classification System into 3 broad areas:
This streaming audio collection contains individual tracks of music, spoken word, and sounds from Smithsonian Folkways Recordings. It also includes readings of literary works, children's music, sound effects and more.