Chopin Early Editions:Digitized images of scores in the University of Chicago Library's Chopin collection
Corpus Mensurabilis Musicae ElectronicumUtrecht University's CMME project represents a collaborative development effort to offer free online access to new, high-quality early music scores.
Juilliard Manuscript CollectionComposers included in this collection include Bach, Beethoven, Brahms, Copland, Debussy, Liszt, Mozart, Schubert, Schumann, and Stravinsky
Tonal CentreAn interactive site for music composers and theorists which explains and demonstrates some of the key concepts of tonality; including chords, scales, cadences, and modulation.