RILM has been the standard for scholarly music resources for many years. When you search, be sure to check out "Major Topics" under Search Options, which includes fields like Ethnomusicology and Pedagogy, making a detailed subject search much easier.
Music in Print is a very specific database which holds information about music that's currently in print and being sold. Use this database to find out information about arrangements of a piece, instrumentation, anthologies, and more.
GIL-Find is VSU's Library Catalog. Click "Advanced Search" to find helpful search options, including limiting "Format" to "Musical Score," or limiting the "Location" to the "FAMC - Fine Arts Media Collection," which contains scores and recordings.
In some cases, Classic GIL may be necessary for your searches instead of GIL-Find. For example, searching for a composer or musical work in the "Author/Uniform Title Browse" will find the authoritative name for which to search for that composer or title.