All scores for music that is no longer under copyright, including the music of all composers before the twentieth century and many from the early part of the century, are now being amassed in this web site (http://www.imslp.org/). There are literally thousands of works available. The database is searchable by composer as well as by melody or instrumentation or genre, and there is also a database of recordings for many of the works, which are playable directly from the web site.
Many of the works studied in Music 784, including all the works of Debussy, Ravel, and Scriabin, as well as most of the works of Stravinsky and Schoenberg, and the early works of Bartók and Berg, and, in the database, and links will be provided to these scores in the repertory.
All music students should be aware and use this resource.